Former Tory chairman Lord Tebbit also warns that legislation could allow him to marry his son to escape inheritance tax

The determination of David Cameron to press ahead with legalising gay marriage opens up the possibility of a lesbian queen giving birth to a future monarch by artificial insemination, Lord Tebbit has warned.

In one of his more outspoken interventions, the former Conservative party chairman told the Big Issue magazine that the legislation could also allow him to marry his son to escape inheritance tax.

Tebbit's remarks indicate that the marriage (same sex couples) bill will have a bumpy ride when it reaches the House of Lords.

Tebbit, who said that ministers have "fucked up" by alienating Tory grassroots, accused Downing Street of forcing through the legislation with little thought.

"The government discussed it for 20 minutes on the morning of its announcement," he told the Big Issue. "They'd done no work on it beforehand."

Tebbit also said he had challenged a minister about legalising gay marriage at the same time as ending male primogeniture in the royal succession.

"I said to a minister I know: have you thought this through? Because you're doing the law of succession, too.

"When we have a queen who is a lesbian and she marries another lady and then decides she would like to have a child and someone donates sperm and she gives birth to a child, is that child heir to the throne?"

Tebbit joked that the change could allow parents to marry their children as a way of avoiding inheritance tax. "It's like one of my colleagues said: we've got to make these same sex marriages available to all. It would lift my worries about inheritance tax because maybe I'd be allowed to marry my son. Why not? Why shouldn't a mother marry her daughter? Why shouldn't two elderly sisters living together marry each other?"

Lord Tebbit, who recently said he could understand why many people vote Ukip, said the party would attract greater financial support if they won the European parliamentary elections next year. He said: "If they make significant gains in the European elections, I know there's people rich enough to get involved and fund a significant campaign at a general election."

1. Gay marriage bill: Labour to table new amendment on civil partnerships
2. Gay marriage bill survives after Ed Miliband votes against amendment
3. The same-sex marriage bill does not live up to its aspiration of equality

Conservative homophobes have held sway in the party against its reforming wing – until now. But can they all be reconciled?

If only those Conservative backbenchers who are now so exercised about the evils of same-sex marriage would swivel their eyes back to the speech David Cameron made a few years ago, they might just understand what the majority of the public really think.

"There is something special about marriage. It's not about religion. It's not about morality. It's about commitment. When you stand up there, in front of your friends and family in front of the world, what you are really doing really means something brave and important. You are publicly saying: it's not about "me, me, me," anymore. It's about "we": together, the two of us, through thick and thin. That really matters. And by the way, it means something whether you are a man and a woman, a woman and a woman, or a man and another man."

The Conservative party has always been a riddle within an enigma regarding homosexuality. It has been rather strange that those who have been intolerant of homosexuals and who think that gays have hijacked "their" party seem blissfully unaware that the friends of Dorothy were very much the friends of Margaret. Her greatest and most influential political secretary, whom she revered, was the openly gay Stephen Sherbourne. Most insiders are of the view that when he left No 10 the slide to her destruction had begun.

It was best summed up by Lord Black, who was once David Cameron's boss at the Conservative Research Department in the 80s: "It was one of those phenomena that, when the Conservative party nationally appeared to be at its most homophobic, at the very heart of the organisation were all these influential gay men. Although everybody knew what was going on, nobody made it very obvious".

This has always fascinated me. There were three champions for the decriminalisation of the wicked homosexuality laws, Enoch Powell, Iain Macleod and Margaret Thatcher. But even Thatcher knew she just could not take her party much further even if she wanted to, which sadly she clearly didn't.

John Major, who first tried to detoxify the party, invited the actor Ian McKellen for a meeting about gay issues. He wanted to repeal section 28 and modernise the equality laws but it would have been impossible. His party were obsessing about Europe to the point of self-destruction.

If you really want to try and understand the disconnect that the Conservative party has traditionally had with homosexuality, it is instructive to trawl though Hansard at the time of the decriminalisation debates in the 50s. Although public opinion had moved in favour of reform this didn't prevent the bigots coming out in force.

Lord Winterton is a fellow worth quoting: "This nauseating subject … fornication and adultery are evils … nothing does more evil or does more harm than the filthy, disgusting, unnatural vice of homosexuality". This tirade came with great hilarity from their lordships as they had just passed the Wankie Colliery bill.

And then there was William Shepherd MP: "Incest is a much more natural act than homosexuality." His speech was followed by his colleague James Dance, "It was the condoning of these offences which led to the fall of Nazi Germany."

But my favourite piece of gratuitous homophobic piece of prejudice of the time came from Sir Cyril Osborne, who brought academic rigour to the debate. "The sponsors of this bill claim that there about one million 'homos' in this country … I do not believe that our country is as rotten as that. It is an awful slur on the good name of the country. I have never come across a homo in this house". I suspect that nowadays Winterton, Shepherd and Osborne would be welcomed into Ukip, the sort of party one instinctively feels watches Roots backwards so that there is a happy ending.

Then of course we suffered the horrors of section 28 and the visceral opposition to equality of the age of consent. When I informed my local association that I intended to vote for equality some of the letters I received were chillingly unpleasant. One old boy, whom I had always regarded as a friend, wrote that I was only supporting the bill because I wanted my eight-year-old son to be sodomised. Scary stuff.

So this is the problem we face today. There are about 32 hardline Tory backbenchers who signed the Westminster Declaration opposing same-sex marriage before the 2010 election. These are the implacable hardliners, the ones who warn us of "aggressive homosexuals" and who tried to derail the gay marriage bill last night.

And what of the rest who have marched through the lobbies? Utterly terrified of the backlash from their local supporters with a dull fear in their stomachs that the Kippers will snatch their seats. How craven. How totally out of touch. How deeply insulting to those who believe that marriage is about love, commitment and fidelity. Whatever gender they might be.

MEP Roger Helmer wrote this: "Homophobia is merely a propaganda device designed to denigrate and stigmatise those holding conventional opinions which have been held by most people through most of recorded history." Helmer now sits on the Ukip benches. I wish that those on the Tory backbenchers who share the same views would join him. They should stop living a lie and come out of the closet and sign up with the Faragistas.

So what do we have? A prime minister who has had the courage and leadership to do "the right thing". Backbenchers who are obsessing about Europe to the point of self-destruction. And local associations who are obsessed that same-sex marriage undermines the fabric of society. It's Conservative groundhog dray.

1. Gay marriage is not a vote-winning policy for the Tories | Peter Kellner
2. MP accuses fellow Tories of trying to ‘derail’ gay marriage bill
3. Gay marriage bill may lead to ‘lesbian queen and artificially inseminated heir’

Labour leader votes against amendment extending civil partnerships to heterosexual couples after appeal by Tory whips

The gay marriage bill has been saved after Ed Miliband agreed at the last minute to vote against an amendment to extend civil partnerships to heterosexual couples that had prompted government warnings that it would derail the entire measure.

The Labour leader, who had planned to abstain in a Commons vote on the amendment, agreed to change tack after the government chief whip Sir George Young sent a message to his opposition counterparts that the Tory leadership was facing defeat.

The move meant that the amendment, tabled by the anti-gay marriage Tory, former children's minister Tim Loughton, was defeated by 375 to 70 votes, a majority of 305.

The decision by the Labour leadership, which has gone from supporting the amendment on civil partnerships to rejecting it within the space of 24 hours, means that the marriage (same-sex couples) bill will now experience a safer journey through parliament.

The government had warned earlier in the day that the Loughton amendment would have threatened the entire bill by adding £4bn to the costs and delaying its implementation. The costs would have come from increased pension survivor rates for new civil partners.

Labour sources said that the party, which had announced earlier in the day that it would abstain on the Loughton amendment after overnight warnings from the government about the threat to bill, denied that Miliband had embarked on a double U-turn.

One source said: "We had an eleventh hour appeal from the government that they did not have the numbers to defeat the Tim Loughton amendment. They made repeated approaches to us at ever increasing levels.

"Ed's overriding priority is to ensure that the bill gets on to the statute book. Ed and Yvette Cooper will therefore be voting against the Tim Loughton amendment. We expect a large number of MPs to join Ed and Yvette. Since there was a genuine threat to the bill Ed decided the best thing to do was to act in this way."

The appeal by Tory whips for Labour support to ensure the safety of the bill highlighted deep divisions in the Conservative party in the wake of claims that a senior member of his entourage described party activists as "swivel-eyed". Lord Feldman, the Tory co-chairman, denied making the remarks.

More than 100 Tory MPs planned to register their opposition to the marriage (same-sex couples) bill by voting in favour of a series of amendments to water down the measure. In the first vote of the evening, more than 150 MPs voted in favour of an amendment that would allow registrars to refuse to perform same-sex ceremonies.

Tory opponents of the bill were alarmed when Labour and the Tories embarked on negotiations during the day. The government agreed during the day to a Labour request to amend its own plans by launching an immediate review into extending civil partnerships to heterosexual couples.

Maria Miller, the equalities minister, agreed to the Labour request. But she suggested that the review could lead to the end of civil partnerships when she said the review will see "if there is a demand for [civil partnerships]".

The deal meant that the government amendment, altered by Labour, was approved by 391 to 57 votes, a majority of 334.

But Labour initially said that it would abstain on the Loughton amendment on the grounds that it agreed with it but did not want to risk the overall bill.

The leaders of all the main parties offered all their MPs, including ministers and shadow ministers, a free votes on the grounds that marriage is a "conscience" social issue in which the party whips have no official say. But the prime minister devoted government time to the gay marriage legislation in the belief that it would help reach out to centre ground voters who may feel uncomfortable about supporting a party whose leader voted in favour of the retention of section 28 as recently as ten years ago.

The divisions among Tories was highlighted when Sir Gerald Howarth, knighted on the advice of the prime minister last year when he sacked him as a defence minister, warned of an "aggressive homosexual community" during a clash with a member of Cameron's policy board. Howarth made the remarks when Margot James, a fellow Tory MP who is in a civil partnership and who was recently appointed to the new Conservative policy board, said that the equal marriage legislation would level the playing field after gay people suffered discrimination in the 1980s.

Howarth replied: "I warn you, and MPs on all sides of the house, that I fear that the playing field has not been levelled. I believe that the pendulum is now swinging so far the other way and there are plenty in the aggressive homosexual community who see this as but a stepping stone to something even further."

1. Gay marriage bill: Labour to table new amendment on civil partnerships
2. Gay marriage bill would be a ‘major step forward’ – video
3. MP accuses fellow Tories of trying to ‘derail’ gay marriage bill

Rebel Tories are defeated in Commons after PM's last minute plea to Ed Miliband

The government's gay marriage bill was saved after David Cameron was forced to rely on Ed Miliband to defeat an attempt by his own MPs to derail the measure by trying to extend civil partnerships to heterosexual couples.

An 11th-hour plea to the Labour leadership by the Tory chief whip Sir George Young, who warned that the government was in danger of losing the vote, prompted a change of heart by Miliband, who had been planning to abstain on the amendment.

The Labour move meant that the amendment, tabled by the anti-gay marriage Tory and former children's minister Tim Loughton, was defeated by 375 to 70 votes, a majority of 305.

The decision by the Labour leadership, which has gone from supporting the amendment on civil partnerships to rejecting it within the space of 24 hours, means that the marriage (same-sex couples) bill will now experience a safer journey through parliament.

But the prime minister, who attempted to reach out to his party by emailing a "personal note" to all members saying that he would never work with anyone who "sneered" at them, suffered the humiliation of having to plead with the Labour party for support. He also saw more than 100 Tory MPs, including the cabinet ministers Iain Duncan Smith and Owen Paterson, vote against him on the first amendment of the day.

The prime minister will understand the dangers of relying on opposition support for a flagship measure after he personally ensured that Tony Blair's schools reforms survived with Tory support in 2006 three months after he became leader. Within months, supporters of Gordon Brown forced Blair to name the date of his departure the following year.

As the debate was under way in the Commons the prime minister moved to shore up his position amid anger in the party over allegations that Lord Feldman, the Tory co-chairman, described grassroots activists as "mad swivel-eyed loons". Lord Feldman strenuously denies having made the allegations.

In his email to party members, Cameron wrote: "I am proud to lead this party. I am proud of what you do. And I would never have around me those who sneered or thought otherwise. We are a team, from the parish council to the local association to parliament, and I never forget it."

But deep divisions in the Tory party were highlighted in the commons when Iain Duncan Smith, the work and pensions secretary, and his long standing ally Owen Paterson, the environment secretary, joined more than 100 Tory MPs to vote against Cameron in favour of an amendment that would allow registrars to opt out of conducting same sex marriage ceremonies. This amendment failed as did an amendment to protect the religious beliefs of a person who believes marriage can only take place between a man and women. All votes were classified as free which meant that MPs could vote according to their consciences.

In one of the most dramatic moments the former defence minister, Sir Gerald Howarth, complained to a lesbian member of the prime minister's policy board about "the aggressive homosexual community". Howarth made the remarks after Margot James, the MP for Stourbridge, said that the legislation was part of recent changes that have created a level playing fields for everyone regardless of sexual orientation.

The prime minister came under fire from the anti-gay marriage MP Tim Loughton after his amendment, which would have legalised civil partnerships for heterosexual couples, failed after the deal between Labour and the Tories. Loughton warned of a "grubby deal" between the two frontbenches as he told MPs: "We are in danger to a stitch up, a last minute stitch up between frontbenches."

The deal was reached after the government had warned earlier in the day that the Loughton amendment would have threatened the entire bill by adding £4bn to the costs and delaying its implementation. The costs would have come from increased pension survivor rates for new civil partners.

The government agreed during the day to a Labour request to amend its own plans by launching an immediate review into extending civil partnerships to heterosexual couples. The goverment had initially said it would do this no later than five years after the passage of the bill, though the equalities minister Maria Miller said the Labour amendment would make little practical difference.

The deal meant that the government amendment, altered by Labour, was approved by 391 to 57 votes, a majority of 334.

But Miller indicated that the review could end up leading to the abolition of civil partnerships once gay marriage becomes legal. She told MPs of the review: "It is important for us to understand what the demand is among individuals who might wish to embark on such an arrangement."

Labour sources said that the party, which had announced earlier in the day that it would abstain on the Loughton amendment after overnight warnings from the government about the threat to bill, denied that Miliband had embarked on a double U-turn.

One source said: "We had an eleventh hour appeal from the government that they did not have the numbers to defeat the Tim Loughton amendment. They made repeated approaches to us at ever increasing levels.

"Ed's overriding priority is to ensure that the bill gets on to the statute book. Ed and Yvette Cooper will therefore be voting against the Tim Loughton amendment. We expect a large number of MPs to join Ed and Yvette. Since there was a genuine threat to the bill Ed decided the best thing to do was to act in this way."

The leaders of all the main parties offered all their MPs, including ministers and shadow ministers, a free vote on the grounds that marriage is a "conscience" social issue in which the party whips have no official say. But the prime minister devoted government time to the gay marriage legislation in the belief that it would help reach out to centre ground voters who may feel uncomfortable about supporting a party whose leader voted in favour of the retention of section 28 as recently as 10 years ago. A source close to Miller said: "We are pleased that the House has accepted our amendment offering a review of civil partnerships and that our warnings around the potential delay to same sex marriage have been heeded. A review is the right way forward and no changes should be made to civil partnerships, without being fully thought through." Tory supporters of the bill were scathing about some of their fellow MPs. One said: "You know how to vote when you see who's in the other division lobby."

One minister said: "We are such an inclusive party we have our own opposition built in. We generally shoot ourselves in the foot and then rely on the Labour party to finish the job for us. And all the time we seem to have a smile on our face."

1. Gay marriage bill: Labour to table new amendment on civil partnerships
2. Gay marriage: Downing Street pleads with Labour to save bill
3. Gay marriage bill survives after Ed Miliband votes against amendment

David Cameron forced to look to Labour to save bill as Tory opponents attempt to limit its scope

Deep divisions in the Conservative party were highlighted late on Monday when Tory MPs clashed during a lengthy debate on the gay marriage bill which survived a series of challenges from traditionalists.

Tory reformers expressed exasperation when a former defence minister warned of an "aggressive homosexual community".

Sir Gerald Howarth, knighted on the advice of the prime minister after losing his ministerial post, made the remarks when Margot James, who was recently appointed to the Conservative policy board, said that the equal marriage legislation would level the playing field after gay people suffered discrimination in the 1980s. James, who is lesbian, said: "I do recall in the 1980s, and even the 1990s, a freezing effect, I would call it, on the lives of gay people and other minorities because at that time the majority were at liberty to discriminate against us in employment and in every other walk of life practically."

Howarth replied: "I warn you, and MPs on all sides of the house, that I fear that the playing field has not been levelled. I believe that the pendulum is now swinging so far the other way and there are plenty in the aggressive homosexual community who see this as but a stepping stone to something even further."

The clash between the two Tories came as traditionalists failed in a series of bids to limit the scope of the bill. An amendment to allow registrars to opt out of conducting same sex marriage ceremonies was defeated by 340 to 150, a majority of 190. An amendment to protect the religious beliefs of a person who believes marriage can only take place between a man and women was defeated by 349 to 148, a majority of 201.

An amendment to extend civil partnerships to heterosexual couples, which had prompted government warnings that the bill could be derailed, was also defeated after the Labour party swung behind the government. The amendment, tabled by the anti-gay marriage Tory, former children's minister Tim Loughton, was defeated by 375 to 70 votes, a majority of 305.

The gulf was so great during the debate that the issue of same sex marriage was a fight as "noble" as the abolition of the slave trade, or but another "stepping stone" for the "aggressive homosexual community". Passions ran high in the chamber even before the supposed "wrecking amendment" on the extension of civil partnerships reached the Commons. The debate opened on the raft of amendments designed to ensure that the bill did not discriminate against teachers, registrars and others opposed to gay marriage on grounds of principle.

David Burrowes, a Conservative MP who proposed a series of amendments, argued: "This is not a marriage bill, it's an unfair dismissal bill" (for registrars and others with conscientious and religious objections).

The nation was, he exclaimed, "as divided" as the Conservative parliamentary party on the issue. And legislation was taking the country "into a whole new terrain of legal challenge". No registrars should be compelled to act against their beliefs or be sacked for adhering to the views held by a majority of Tory MPs and "millions of others in this country".

Where Burrowes saw potential conflict, the Labour MP Stephen Doughty, (Lab, Cardiff South and Penarth) saw harmony, literally.He said the Commons should "look at the celebrations and happiness in New Zealand", when they signed their own same-sex marriage bill, which manifested itself in "the singing of love songs". He hoped for that here, too, "though perhaps not the singing", he conceded.

The veteran Conservative Edward Leigh called for people who disagreed with gay marriage to be given protection under the Equality Act 2010. This was not, he assured the House, because he was "swivel-eyed", though he conceded he became a bit cross-eyed late at night when tired. Nor was he "myopic".

Neither was it to defend those who were being "beastly" or "horrid" to gay people in the workplace. "But I do think actually that same-sex marriage is different. It seems to many of us, if you dare to disagree with the new orthodoxy that gay marriage is the best thing since sliced bread, you are somehow breaking a new social taboo, you are doing something in your workplace, particularly in the public sector, that you should not be doing."

When there was a clash between gay rights and religious freedom, in law gay rights came first, Leigh said. Citing an example of a housing association worker who was demoted for writing on Facebook that gay marriage was "an equality too far", he said the government was legislating in a culture that had been "so coloured by political correctness" that "mild-mannered people expressing reasonable beliefs in moderate tones are treated like villains".

The "outlandish views of the loony left of the 1980s" had become "embedded in high places".

But the former Labour minister David Lammy said there should be an obligation on public servants to teach about gay marriage, as it would the law once the legislation had passed. He spoke of the "Windrush generation", who arrived in Britain to signs reading "No Irish, no blacks, no dogs". "That was illegal", he said, and the Commons had declared it to be wrong.

Referring to the abolition of the slave trade in the 19th century, he said: "There was a split in this house for 20 years on whether black human beings were human or chattel." "That is why this is a noble fight, "he said.

1. MPs debate gay marriage bill: Monday 20 August as it happened
2. Gay marriage: Downing Street pleads with Labour to save bill
3. Gay marriage bill: Labour to table new amendment on civil partnerships

Downing Street has said amendment to gay marriage bill could cost £4bn, but Labour and others have questioned figure

It was the big number in Monday's front-page stories: Downing Street's warning that the bill to legalise gay marriage could cost an extra £4bn.

This, it was claimed, is how much a Tory backbench amendment would cost which would allow straight couples to enter into civil partnerships, thereby equalising treatment between the two groups. Labour and others scoffed at the total.

So is the £4bn figure accurate?

It is possible that allowing straight couples to enter civil partnerships would cost a significant amount. One of the reasons why gay rights campaigners want access to marriage is because it offers more generous pension entitlements.

The £4bn figure was first touted last week by the DWP pensions minister Steve Webb, who believed the liability would follow as the government would be forced to change the pensions rules. These currently discriminate against those in civil partnerships. If the positions were equalised, couples currently in civil partnerships would benefit from uprated pensions should their partner die. In effect it would be untenable under pensions rules for some straight couples in civil partnerships to get different treatment from straight couples in marriages.

If this change occurred, all those currently in civil partnerships – who the government is assuming would not otherwise bother to convert their legal status to marriage – would also end up getting better pension settlements when their partners die.

But is the £4bn figure right? No: on Monday afternoon the Treasury admitted the figure had nothing to do with any actual estimation of costs that the amendment would create. Although the understanding of how the liabilities could arise is right, a Treasury spokesperson said the figure was meant to be "illustrative" only.

The costing was taken from government evidence in the 2011 legal battle Cockburn v the secretary of state for health, which, although it was about pensions, surviving spouses and equal treatment, had nothing to do with civil partnerships.

"[It] is a figurative example that the minister uses to exemplify what happens when you start to run into equalising rights for people. There are costs to [doing] that," a Treasury spokesperson said.

1. Gay marriage bill: will extending civil partnerships really cost £4bn?
2. Gay marriage bill: Labour to table new amendment on civil partnerships
3. Should civil partnerships be extended to heterosexual couples? | Poll

Leading Tory MPs is far harder than herding a sackful of kittens

No sign of David Cameron in the Commons chamber. Perhaps he was lying in a darkened room, or consulting a hermit on top of a Himalayan mountain. His party appears to be disintegrating into endless factions beneath him. Loonies versus sort-of sane. Swivel-eyed against glass eyed.

Herding cats? By comparison, a sackful of kittens would be as easy to marshal as the Brigade of Guards. If they were football fans, hordes of police would be needed to keep Tory MPs at opposite ends of the stadium.

On Monday we started the last stages of the gay marriage bill, beginning with the timetable. Peter Bone (D, Wellingborough), the skull beneath the skin, laid down a marker.

There wasn't enough time for the debate. "It was really appalling when Labour did it; it is absolutely appalling when we do it!" he said. "You're worse than that lot!" – not the message Cameron was hoping for.

Sir Peter Bottomley (C, Worthing W) was, I think, in favour of gay marriage, which he compared to the Reform Act, the abolition of slavery and women's suffrage. MPs love to believe they are on the cusp of history.

Sir Gerald Howarth (C, Aldershot) said that the Commons might have voted in favour by a large majority, but only a minority of Tories had backed it.

A new constitutional tenet: a bill doesn't just need most MPs; it needs the support of most MPs who agree with Sir Gerald!

Edward Leigh (C, Gainsborough) thought they ought not to be considering the bill at all: "We should be concentrating on the catastrophic destruction of the public finances created by the party opposite!"

Another constitutional innovation: MPs should not pass laws if they could be abusing the Labour party instead.

Next we were onto protection for people who opposed gay marriage, whether ministers of religion or teachers. According to the amendment, teachers would not have to discuss gay marriage if they were opposed.

I wondered what would happen when – and if – Elton John gets married, an event which, making one of Jay Gatsby's parties look like a Methodist tea party in scout hut, may just make it onto the TV news, so undoing all the dogged silence of some teachers.

Daniel Byles, (C, N. Warwicks) thought the chaos was good news, proof that MPs were in tune with the public.

"The nation is deeply divided, and we have shown that we are in touch with the nation by our own divisions." Eh?

The bonkitude was not confined to opponents. Stephen Doughty (Lab, Cardiff & Penarth) wanted us to follow the example of the New Zealand parliament where legalising gay marriage had led to "a feeling of happiness and the singing of love songs!" MPs were baffled.

What should they be singing? Smokey Robinson's I Second That Motion, obviously, Here Come The Grooms, or Going To The Non-judgmental Chapel Of Love, perhaps

Edward Leigh was back. He feared that the bill might allow people to be "beastly" to each other. "Freedom of conscience does not mean freedom to be beastly to anyone!"

He was asked about teachers.

Should a science teacher be allowed to teach creationism? Mr Leigh thought yes, "if creationism became a quasi-religious belief, which in fact it already is." So people who think dinosaur bones have been planted by Satan to stop people believing in Genesis should be set loose in our schools – provided they believed it sincerely.

Mr Leigh tackled the optical issue. "My wife says as I get older, I am sometimes cross-eyed. I am not swivel-eyed, but if you called me cross-eyed I could take you to court!"

This was getting crazier. Sir Gerald said that it didn't matter what parliament decided: "We have ceded our powers to the European Court of Human Rights." Bingo! He had melded the two great hate-Cameron issues into one!

The prime minister must feel he's at the end of The Great Gatsby, "beating on, boats against the current, borne back ceaselessly into the past".

1. Martin Rowson on the ‘swivel-eyed loons’ row – cartoon
2. David Cameron ally: Tory activists are mad, swivel-eyed loons
3. Cameron had the chance to defy the ‘swivel-eyed loons’ and remake his party. He failed | Steve Richards

1. Gay marriage bill: Labour to table new amendment on civil partnerships
2. Gay marriage: Downing Street pleads with Labour to save bill
3. MP accuses fellow Tories of trying to ‘derail’ gay marriage bill

Yvette Cooper says Labour will put forward its own amendment after issue of civil partnerships threatens to derail bill

The Labour leadership has moved to save the equal marriage bill by tabling its own amendment on civil partnerships for heterosexual couples – the area that had threatened to derail the entire measure.

Yvette Cooper, the shadow home secretary, said Labour would withdraw its support from an amendment tabled by Tory opponents of gay marriage and table its own amendment calling for an immediate consultation on extending civil partnerships to heterosexual couples.

Labour's earlier support for the amendment, due to be tabled by the former Tory children's minister Tim Loughton, had prompted a warning from Nick Clegg that the bill could be derailed.

Cooper confirmed that the Labour leadership, which is allowing its MPs a free vote, would abandon its support for Loughton and would instead table its own amendment to save the bill.

The shadow home secretary told The World at One on Radio 4: "We would urge the government, we would urge the Liberal Democrats, we would urge backbenchers of all parties to support this [Labour] amendment to allow the bill to pass without the Tim Loughton amendment for the time being but also allowing an immediate consultation to start on the opposite-sex civil partnerships. On that basis we would recommend to people not to support the Tim Loughton amendment."

Cooper added that she was acting to save the bill. She said: "It would allow the bill to keep making progress and to prevent either the government or some of the Tory backbenchers using this as an excuse to wreck the bill or delay the bill. We don't want anybody to use this as an excuse to wreck the bill, including the government.

"We want to make sure the government doesn't use this [the Loughton] amendment as an excuse to delay or wreck the bill because we know they have become very nervous about the infighting on the Tory benches. We know David Cameron's leadership is too weak to be able to push this through and to be able to get support on his own benches. We think that is a serious problem. But also we don't want to see gay couples who are desperate to set the date and get married find themselves at the mercy of this Tory infighting and this row which is not rational any more."

The intervention by Labour, which follows a warning by the government that extending civil partnerships to heterosexual couples could cost £4bn a year and delay the introduction of the bill until after the 2015 general election, means that the Loughton amendment will now struggle to succeed. Cooper said: "What we have put forward is a proposal to have an immediate consultation on opposite-sex civil partnerships. We think you could start that straight away. You don't even need to wait for the bill to go through."

Downing Street is deciding how to respond to Labour, which will probably have to table the amendment at a later stage because it is too late to table amendments for Monday's business. No 10 tried to see off the Loughton amendment by calling for a review of civil partnerships five years after the equal marriage bill enters law. This was rejected by Labour, which was highly dismissive of the government claims of an extra £4bn in costs.

Cooper said: "[Our amendment] would allow us to challenge some of the government's facts and figures which we do think are not very credible. I don't see why it would need to cost £4bn. That feels like a figure that has been plucked out of thin air."

1. Gay marriage: Downing Street pleads with Labour to save bill
2. Gay marriage bill in danger of being hijacked, warns Nick Clegg
3. MP accuses fellow Tories of trying to ‘derail’ gay marriage bill

Deputy PM ups stakes hours before MPs vote as Maria Miller warns Tories against 'wrecking' amendment on heterosexual civil partnerships

Nick Clegg has upped the stakes hours before MPs vote on the gay marriage bill by warning that the Labour party could derail the entire legislation if it joins forces with Tory opponents to vote in favour of granting civil partnerships to heterosexual couples.

As the equalities minister, Maria Miller, warned of a risk to the bill, which could add £4bn in costs and delay its implementation until after the 2015 general election, the deputy prime minister expressed concerns that the measure was being hijacked.

Clegg and Miller went on the offensive on Monday after government sources warned that Labour could be in danger of killing off the bill if it succeeds – in conjunction with Tory opponents of gay marriage – in amending the measure to legalise civil partnerships for heterosexual couples.

The deputy prime minister supports this proposal but will not vote with Labour because he fears the amendment could wreck the bill. Speaking at an event hosted by the crime reduction charity Nacro in London, the deputy prime minister said: "The bottom line is I will do whatever I judge is best to safeguard the bill and to make sure it doesn't become hijacked by those whose ulterior motive is actually to discredit or to derail the legislation.

"In principle this is something we have long supported but I don't want to lose the wood for the trees. I want this bill to be passed and for the bill to do what it says on the tin, which is to provide equal rights to marriage for same-sex couples and that will be my overriding objective."

Downing Street confirmed that David Cameron would join Clegg and Miller in voting against the amendment, to be tabled by the former Tory children's minister Tim Loughton. The prime minister's spokesman said: "The equal marriage bill is about the extension of marriage. There have been concerns and issues raised in the House with regard to civil partnerships and that is why the government has proposed a formal review of civil partnerships.

"The prime minister is a big believer in marriage and that is why he thinks gay people should be able to get married." Miller gave the strongest indication that Downing Street would shelve the bill if fundamental changes were made as she warned that opponents were in danger of "giving the government a headache".

The intervention by Miller, hours before MPs vote on amendments to the marriage (same-sex couples) bill, marked an intensification of government warnings over threats to the legislation.

Downing Street is prepared for a bruising day on Monday as up to 150 Tory MPs prepare to show their unease with Cameron by voting to give teachers and registrars a series of exemptions. These are likely to fail because the bulk of the Labour party and the Liberal Democrats will join forces with enough Tory MPs to ensure the exemption amendments fail. All votes are free because the bill has been designated a matter of conscience by all the parties.

But Downing Street believes it will be defeated because most Labour MPs are prepared to vote with Tory MPs to amend the bill to allow civil partnerships to heterosexual couples. The government, which regards this as a wrecking amendment, warned on Sunday that the amendment on civil partnerships could cost £4bn. Sources also warned it would delay the implementation of the bill by two years.

Miller stepped up the pressure on Labour to abandon its support for the amendment when she warned of a risk to the bill. She told BBC Radio 4's Today programme: "I want to be seeing marriages being undertaken under this new bill as early as next summer. To actually put in at this stage such a fundamental change risks that, and it risks significant delay. Those that are supporting it need to be very aware of that."

Asked whether the amendment would derail the bill, Miller said: "I think it would throw up significant challenges. Obviously, it would be for us to go through a consultation and a consideration period to understand how that would work because at the moment there really isn't the detail there … It throws up a headache because those that remember the issues round the civil partnership bill will remember it took some two years to finalise."

Labour believes Miller is attempting to clear the way for No 10 to abandon the bill as the prime minister attempts to appease Tory activists who are strongly opposed to the measure. Loughton, who is tabling the civil partnership amendment, accused the government of scaremongering, and said the warning of a £4bn cost was a "back-of-the-fag-packet" calculation.

But Miller identified three threats to the bill if the Loughton amendment were passed:

• A "whole new cadre" of opposite-sex civil partners would be entitled to pensions.

• Westminster has no power over marriage in Scotland and Northern Ireland. There would be considerable issues to negotiate.

• International recognition of heterosexual civil partnerships would have to be examined.

Miller said: "These are very practical issues, very important issues. They are issues that need to be looked at if we are to legislate. I think it would not be responsible to legislate in this way at this point in time."

But the equalities minister declined to mention the £4bn "price tag" highlighted by government sources on Sunday. She said the cost of equalising pension survivor rights in contracted-in and contracted-out schemes would be about £90m. But equalising rights for widows and widowers would lead to higher costs.

Miller said: "It would make a fundamental difference to the passage of the bill because what the amendment [to extend civil partnerships to heterosexual couples] is trying to do is to import in a very complicated concept, which took more than 200 clauses to explain in the original civil partnership bill, into a bill which is all about extending marriage. It is trying to do that in just two very short amendments.

"It introduces complexity, which would not only delay the passage of the bill through parliament but … would also put forward a number of quite fundamental policy issues which would need considerable thought and consultation."

At least two cabinet ministers – the environment secretary, Owen Paterson, and the Wales secretary, David Jones – are prepared to vote for separate amendments that would grant exemptions to teachers and registrars. Chris Grayling, the justice secretary, and John Hayes, the prime minister's unofficial envoy to the Tory right, may also side with opponents of the bill in the votes.

But Labour rejected what it called the farcical warnings, as sources noted that the supposed size of the price tag had grown from £3bn to £4bn in five days. One source said: "They are wrecking this bill themselves and trying to blame others."

Loughton accused the government of scaremongering after warning about the dangers supposedly posed by his amendment. He told the Guardian: "This scaremongering just won't wash. The government has come up with a lot of desperate last-minute excuses as to why giving full equality of civil partnerships will not work. This is what comes when you try to redefine marriage without having thought through the consequences.

"One of those consequences is that the majority of the population and MPs clearly want equality for civil partnerships. The government bill, as it stands, will deny them that equality. So they need urgently to do the work to make it happen."

Last night Loughton tweeted: "£4bn is back of fag packet scaremongering particularly if Govt doubt straight couples want civil partnership."

1. Gay marriage: Downing Street pleads with Labour to save bill
2. MP accuses fellow Tories of trying to ‘derail’ gay marriage bill
3. The same-sex marriage bill does not live up to its aspiration of equality