Gerald Howarth, a junior defence minister, told The Daily Telegraph that Tory MPs should not be forced to support the proposal to rewrite the legal definition of “marriage” so that it included same-sex couples.
His concerns were echoed by other Conservatives who warned that the issue was causing disquiet on the back benches and could even lead to ministerial resignations.
Mr Cameron told the Tory conference in his speech on Wednesday that he supported homosexual marriage “because I am a Conservative”. He argued that “commitment” in a relationship should be valued regardless of whether it was between a man and a woman or within a homosexual couple.
The Most Rev Peter Smith, the Roman Catholic Archbishop of Southwark, led the religious criticism of the Prime Minister’s comments. The Church of England is expected to oppose the plan when the Coalition begins a formal consultation in the spring.