Gay marriage should not be a not a priority for the government, a senior Tory said on Sunday.
Former defence secretary Liam Fox added his voice to calls for the government to concentrate on other issues such as the economy rather than force through legislation to introduce gay marriage.
Speaking on Sky News, Dr Fox said: "This is a contentious issue but I have to say that I am much more in favour of social mobility than social engineering.
"I think that the vast majority of the public have a completely different set of priorities from what I would call the metropolitan elite and I think they will be looking for economic and social issues to be dealt with first."
The debate has been a source of division in the coalition Government.
Recently, the Deputy Prime Minister Nick Clegg said gay marriage should not be left to MPs' consciences but the Tories will be allowed a free vote to avoid a rebellion from those opposed to the issue.
Critics have questioned Cameron's commitment to the reform after he conceded to a free vote to quash an expected a rebellion among backbench Tories.
Conservative Northern Ireland Secretary Owen Paterson has also declared his opposition to same-sex marriage in the most high-level challenge to Cameron so far on the issue, while defence minister Gerald Howarth is also against the move.
A poll last March found half of the Conservative party's supporters are against legalising gay marriage in principle, with just 35% in favour.