A group of current and former Conservative constituency chairmen has handed in a letter to No 10 urging David Cameron to rethink his plans to allow gay marriage.
Tory grassroots feel “a sense of betrayal” over the Prime Minister’s “bulldozed-through” reforms, party activist claim.
It comes amid suggestions that around 180 Conservative MPs are preparing to oppose or abstain, including a significant number of Cabinet members, junior ministers and party enforcers, when the proposals are voted on for the first time.
Culture minister Ed Vaizey insisted: “Is this going to tear the Tory party apart? No, I don’t think it will. I think there is a difference of opinion among colleagues but it is a civilised debate.”
However, former children’s minister Tim Loughton warned the Bill was “full of pitfalls” and would “set MP against MP”.
Edmund Costelloe, who quit as chairman of Somerton and Frome Constituency Conservative Association last month over the policy, said: “It has been bulldozed through. It wasn’t in the manifesto.
“Many, many people would not have voted for candidates had it been known. There is a sense of betrayal.”
And Geoffrey Vero, chairman of the Conservative association in Surrey Heath where Education Secretary Michael Gove is MP, warned the move “may seriously affect David’s opportunity to get re-elected at 2015”.
However, human rights campaigner Peter Tatchell staged his own protest outside Downing Street as the letter was handed in, waving a placard which read “End ban on same-sex marriage. Marriage equality!”.
Mr Tatchell, national coordinator of the pro-gay marriage campaign Equal Love, said: “The Conservative rebels do not represent most Tory supporters.
“Opposition to equal marriage by some Conservatives is reviving the ‘nasty party’ image and turning off voters. It undermines David Cameron’s attempt to detoxify the Tory brand and present a more caring, compassionate Conservatism.
“The Prime Minister’s backing for marriage equality is making many voters more sympathetic to the Conservatives.”
MPs will vote on the proposals, which will also allow civil partners to convert their partnership to a marriage and enable married people to change their legal gender without having to end their union, for the first time when the Marriage (Same Sex Couples) Bill has its second reading.
Mr Cameron views the introduction of same-sex marriage as the “Conservative Party delivering the promise it made”.