Two Westcountry MPs have signed up to a cross-party alliance opposed to Government plans to legislate for same-sex marriages.
In total, 58 parliamentarians – including 35 Tory MPs – have put their names to an open letter to the Daily Telegraph warning ministers they have no mandate for the proposed change.
Among them are Anne Marie Morris (Con, Newton Abbot) and Richard Drax (Con, South Dorset).
Mrs Morris said: "I signed the cross-party letter, alongside many other colleagues, because I have reservations about redefining how we understand marriage.
"It is clear that there are widespread concerns about the proposals and I hope these are taken into consideration as we move forward."
Writing on his blog earlier this year, Mr Drax said: "I was brought up in a Christian family and 'marriage' in my view is between a man and a woman, and always will be.
"We have no mandate to redefine 'marriage' and it would be an abuse of power to push this through the Commons on the whim of a Prime Minister, whose motives I really do query."
Among the signatories are former Conservative leadership challenger David Davis, ex-ministers Tim Loughton, Sir Gerald Howarth and Sir Jim Paice, and the former Archbishop of Canterbury, Lord Carey of Clifton.
The letter says: "At the last election, none of the three main parties stood on a platform to redefine marriage. It was not contained in any of their manifestos, nor did it feature in the coalition's programme for government.
"We understand some parliamentarians support freedom for same-sex couples to marry, but we support a freedom from the state being able to redefine the meaning of marriage."
There is deep anger among traditionalists in the party who say it is out of step with the instincts of their natural supporters and is driving away the activists they need to campaign for them. Culture Secretary Maria Miller has sought to reassure opponents with a "quadruple legal lock" guaranteeing that no religious organisation or minister will be compelled to conduct a gay wedding against their wishes. However, many remain unconvinced, fearing it would be open to challenge in the European Court of Human Rights. The legislation is expected to pass with overwhelming support from Labour and the Liberal Democrats.