Cameron warned against gay marriage climbdown

Michael Ashcroft is accused of running Johnston International, a construction firm on the Turks and Caicos Islands (Rex Features)

David Cameron has been warned by the former Tory deputy chairman Michael Ashcroft that he will do himself political damage if he gives in to the Tory right by abandoning plans to legalise gay marriage.

Based on opinion polling, which the billionaire peer commissioned himself, Lord Ashcroft concluded: "If the Prime Minister were to drop his plans to introduce gay marriage he would be unlikely to win many back on the strength of it.

"People who oppose gay marriage would remember that he was in favour of it before the going got tough. Those who support it would see that he abandoned the idea in the face of a determined minority. Those who don't much care either way would notice another flip-flop."

His findings showed how little the public is bothered by the issue. Most people did not know that it was on the political agenda, and more than a quarter said they had no opinion on it, either way.