Politicians 'have no right to meddle with marriage'
Some Conservative MPs are still hoping the prime minister can be convinced to drop the bill which is due to get to the Commons next Tuesday.
The Today programme's Justin Webb has been to north-east London, where the local Conservative MP David Burrows says many of his constituents have been voicing their opposition to gay marriage.
Ann Fennel, a member of the public who wrote to Mr Burrows, said: "The name Conservative, one would think they'd be conserving the ancient institutions, and this is something that has been an institution for years.
"Instinctively I feel very uncomfortable about it. The bible is quite explicit that two men together is a sin"
Another, John Boast, who has stood for parliament himself, said: "If my MP were voting [in favour of gay marriage], I would not be voting for him at the next election.
"This is a gross interference in something which politicians have no right to meddle in. This is a hundreds of year old institution."
First broadcast on BBC Radio 4's Today Programme on Friday 1 February 2013.