The plans are being championed by the Liberal Democrats, who are also pursuing full “marriage” rights for same-sex couples.

They have received the support of the Quakers and Christian LGBT groups but strong opposition from other sections of the church.

Dr John Sentamu told BBC One’s Andrew Marr show: “I live in a liberal democracy and I want equality for everybody. I cannot say the Quakers shouldn’t do it.

“Nor do I want somebody to tell me the Church of England must do it or the Roman Catholic Church must do it because actually that is not what equality is about.”

It is expected that any legislation passed will allow churches and other religious settings to choose whether or not they host civil partnership ceremonies but some Christians are still concerned that the religious freedom of churches will be compromised.

Speaking on BBC Radio 4’s Today Programme, the Rev Rod Thomas, of orthodox Anglican group Reform, said that even if changes to the law safeguarded the right of Christians to opt out of conducting gay civil partnership ceremonies in their churches, the likelihood was that churches would be unable to refuse in practice.

“It’s perfectly right that what’s happening isn’t compulsion but the fact is that if you give a right for anything to happen, as we have discovered in Europe, it quickly has perverse legal effects so it will only be a matter of time before someone starts a legal action against some vicar for discriminating against them [a gay couple] by refusing to allow them to have their ceremony in the church,” he said.

“What we’ll end up with is a government committed to reducing legal burdens and protecting freedom ending up passing legislation that will haul vicars before courts and eventually undermine freedom.”

The Rev Preb David Houlding, of Forward in Faith, an orthodox group in the Church of England, said it was not up to the Government to tell the Church what to teach.

He remained optimistic, however, that changes to the law in this respect would prove to be a “non-issue” for the Church so long as it was granted exemption from such legislation.

“Civil partnerships and marriage, which is between a man and a woman, are not the same thing. The problem is we are confusing the two,” he said.

“The Church of England is obliged to marry people if they so wish but civil partnerships are not the same as marriage and therefore the Church of England could not be obliged to ‘do’ gay marriage because there is no such thing.

“It is not up to the Government to tell the Church what to teach. That would be altering the teachings of the Church and the Church is quite clear about what it teaches – that marriage is between a man and a woman.”

Dr Lisa Nolland, a consultant to orthodox group Anglican Mainstream, said it was important that Christians speak out against changes to the law.

“It is not enough for Christians to know what is happening. People have got to do something. They must pray and act,” she said.

“If these plans are introduced, then it may be optional today but in six months’ time, if your church isn’t ‘gay friendly’ then you may find yourself in all sorts of difficulties, such as not being able to access funds for community projects. The church must find its voice.”