The coalition’s controversial gay marriage legislation returns to the Commons later with Tory MPs and activists deeply split over the issue.
The move has been championed by David Cameron but he has faced Conservative opposition at all levels from the grassroots to the Cabinet.
A group of more than 30 current and former local party chairmen warned that the plans would drive Tory voters to the UK Independence Party and make a Conservative election victory in 2015 impossible.
Chairman of the Conservative Grassroots group Bob Woollard which organised the protest letter to the Prime Minister, said: “Same sex marriage is really a tipping point, a bellwether issue if you like – people have just said ‘I’ve had enough, I’m off, I will never vote Conservative again’.
