A NORTH-East Conservative MP is on a collision course with David Cameron after revealing his plans to vote against gay marriage.

James Wharton, the Stockton South MP, described the policy as "a step too far" - just a week after the prime minister vowed to "get it done and get it done quickly".

In a letter to constituents, Mr Wharton backed the freedom for same-sex couples to enter into civil partnerships, describing them as "an important step towards recognising the value of all loving relationships".

But he raised fears that any move to legalise gay marriage would, because of EU law, force churches to perform ceremonies - despite promises to the contrary.

And he wrote: "I am, therefore, minded to vote against this change, when it comes before parliament, though I will, of course, look at the detail of the proposals when the time comes."

According to one survey, more than 100 of the 303 Conservative MPs have written to constituents indicating their unease about gay marriage.

That threatens with Mr Cameron with the biggest Tory rebellion in modern times, explaining his decision to grant his MPs a free vote on the controversy.

Nevertheless, the Commons appears certain to vote in favour of gay marriage, because of strong backing from Labour and the Liberal Democrats.

That vote is now expected to be staged early in the New Year, after No.10 decided to try to head off a gathering campaign among the Tory grassroots against the move.

Previously, the government had suggested only that gay marriage would be introduced at some point before the 2015 general election.

At the Tory conference last year, the prime minister: "I don't support gay marriage despite being a Conservative. I support gay marriage because I'm a Conservative."

Recently, George Osborne upped the stakes by arguing the Tories risked losing the next general election if they refused to make the change.