David Cameron risks upsetting grassroots Tory activists over gay marriage backing

David Cameron risks upsetting the grassroots Conservative activists whose help he will need at the next general election if he presses ahead with plans to legalise gay marriage, the chairman of the party's National Convention warned today.

Emma Pidding, whose organisation represents volunteers within the party, said she was concerned about the possible impact on the Tory election campaign if the plans for same-sex marriage go ahead.

The Government launched a consultation on the proposals earlier this year, and Mr Cameron was last week reported to have told gay groups he was determined to push the change through by the time of the election in 2015.

Ms Pidding today told BBC Radio 4's World At One: "My concern is that we are potentially upsetting our members and activists when I have one goal, and that is to obtain a Conservative majority government in 2015.

"Anything which upsets any of my members, I don't like to see that."

Ms Pidding said the issue of gay marriage was of passionate interest to "a few individuals" on either side of the argument but was not a priority for most Tories.

Conservative MP David Burrowes - a vocal critic of the proposals - said gay marriage was the kind of issue which might be a determining factor for a significant number of voters in crucial marginal seats, like his Enfield Southgate constituency in north London.

"The issue is one that is vote-defining for many people," Mr Burrowes told the programme. "Even in my constituency where they know that I am firmly opposed to the proposal, people say that if that does go through as legislation, then they won't vote for me.

"That must concern me and it concerns many other colleagues in marginal seats."

Mr Cameron gave his support to same-sex marriage at last year's Conservative conference when he said: "I don't support gay marriage despite being a Conservative, I support gay marriage because I'm a Conservative."

Backbench MP Mark Pritchard said he was waiting to see if the Prime Minister would make similar comments at this autumn's gathering in Birmingham.

"I think in the desire to so-called decontaminate the Conservative brand, there are those that may end up damaging our Conservative brand with our natural supporters and voters in the country, and most importantly our grassroots who support us financially and deliver leaflets day-in day-out up and down the country," warned Mr Pritchard.

"We need those people and we shouldn't take them for granted."

But Matthew Sephton, the chairman of LGB Tory - an organisation for lesbian, gay and bisexual Conservatives - told World At One that opponents of same-sex marriage were a "vocal minority" in the party but did not represent voters at large.

"You only have to look at the latest YouGov polls produced in conjunction with Stonewall, where 71% of the general public are shown to support the Government's commitment to same-sex marriage," said Mr Sephton.

"There are a huge number of LGB activists within the Conservative Party as well, and it is also the case that they shouldn't be taken for granted.

"We have got a vocal minority at the moment who have perhaps been too vocal and we who believe in the Government's priorities need to be more vocal as well.

"At the end of the day, as David Cameron has said, we need to be on the right side of history and I think the Government's proposals to introduce same-sex marriage will put us on the right side of history."