Tory MPs are engaged in a "dark" and "cynical" move to wreck the gay marriage bill equality campaigners have warned, as the government prepares to lose a key vote in the Commons on Monday.
The Marriage (Same Sex Couples) Bill returns to the Commons today for two further days of debate today. MPs led by Conservative Tim Loughton have tabled an amendment that would expand civil partnerships to include heterosexual couples.
Reading East Mp Rob Wilson, who supports the Loughton amendment, told HuffPost UK it was needed as allowing gay people to marry but preventing straight people from having civil partnerships would be a "new inequality".
However Lib Dem minister Lynne Featherstone said she doubted Loughton, Wilson and their colleagues had suddenly become converts to the cause of equality.
"Given their public statements I fear what is at work here is rather darker and more cynical – a deliberate attempt to wreck the legislation by introducing extra issues to it that will make it easier for opponents of equal marriage in Parliament to then filibuster, delay and block the legislation," she said.
Featherstone, who introduced the bill while serving as equalities minister, warned MPs who support gay marriage as well as civil partnerships for straight couples to "beware opponents bearing gifts".
"The people pushing this change are not those with records of supporting equality and marriage rules that accommodate a diversity of couples," she said.
Gay rights campaign group Stonewall has also written to all MPs to say it is “concerned that commencement of this important final measure of legal equality for same-sex couples risks being delayed by proposed amendments which would widen the Bill beyond its clearly defined purpose".
And government sources have been keen to point out that the Church of England is opposed to allowing heterosexual civil partnerships as it would add to the "confusion about the place of marriage in society".
Damian Collins: Freedom Cuts Both Ways in the Gay Marriage Debate
The government is not necessarily opposed to expanding civil partnerships - but fears adding it to the bill would come at a huge cost as well as significantly delay the introduction of gay marriage.
Culture secretary Maria Miller has offered to launch a review into the future of civil partnerships in an attempt to prevent defeat in the Commons today. However the amendment has the backing of both opponents and supporters of gay marriage - including the Labour Party.
Miller has urged her Labour shadow, Yvette Cooper, not to vote in favour of the Loughton amendment. Cooper, who supports same-sex weddings along with the vast majority of Labour MPs, has warned her party not to "get dragged into vortex of Tory in-fighting".
The culture secretary told BBC Radio 4's Today programme this morning: "It introduces complexity which would not only, I believe, delay the passage of the bill through Parliament, but it would also put forward a number of quite fundamental policy issues which need considerable thought and consultation, let alone any delays around implementation."
On Sunday Tory activists attacked David Cameron's support for gay marriage, claiming it had made winning the next general election "virtually impossible".
In a letter to the prime minister, more than 30 present and former local party chairmen warned that Cameron's backing for a change in the law had led to voters switching their support to Ukip.
However a competing letter, signed by over 125 Senior Conservative Party activists including association chairmen, urges the prime minister not to back down. "This is an issue of particular importance to younger voters and MPs risk appearing out of touch if they pander to a vocal minority," they said.
David Burrowes MP: It Is Time to Support the British Traditions of Free Speech, Tolerance - And MarriageSuggest a correction