Out4Marriage, Peter Tatchell and the leader of the Labour Party Ed Miliband have this evening raised concerns over the decision to formally ban the Church of England from performing same-sex marriages.

The bill will explicitly state that it would be illegal for the Church of England and the Church in Wales to marry gay couples, or to opt-in to do so.

Canon law – which bans the marriage of same-sex couples – will continue to apply; meaning it would require a change in both primary and Canon law before the Church of England and the Church in Wales would be able to provide marriages for gay couples.

Ed Milliband said: “It is disappointing that the government is making same-sex marriage illegal in the Church of England.”

James-J Walsh, of Out4Marriage, said that while it broadly welcomed the government’s plans, he said the solomenising of same-sex marriages should be “a theological debate, between religious institutions and their congregation, and no enforced bar should be put in place by the state”. He added: “Maria Miller is right to seek protections for religious belief, from judicial interpretation, but in so doing should avoid future inequalities.”

He said that the current proposals “require another Act of Parliament to undo, creating future possibility where religious freedom is limited by statute, rather than religious belief, and could, unless fully thought about, have the exact opposite intention to its purpose”. He said: “The problem is further exacerbated because this special lock will only be in place for the largest faith in England and Wales – the Church of England and the Church of Wales.”

Human rights campaigner Peter Tatchell said: “Exempting the official established church sends the wrong signal. There is no reason why these churches should be treated differently from other faiths.

“This faith-based discrimination could be open to legal challenge. The government is treating two churches differently from all other religions. Discriminating between faith groups is probably illegal under the Human Rights Act and the European Convention on Human Rights.”