Senior church leaders and politicians fear that clergy might be taken to court if they refuse to allow homosexual civil partnership registrations to take place in church.
The warning comes after the House of Lords voted to back an amendment to the Equality Bill that allows, but does not compel, churches to host civil partnership registrations.
But there is widespread concern that the move will open the way for costly litigation against church ministers who refuse.
The Rt Revd Michael Scott-Joynt, the Bishop of Winchester, said: “I believe that it will open, not the Church of England, but individual clergy, to charges of discrimination if they solemnise marriages as they all do, but refuse to host civil partnership signings in their churches.
“Unless the Government does something explicit about this, I believe that is the next step.”
The Bishop of Bradford, the Rt Revd David James, warned during the debate on the amendment of “unintended consequences”. He said that although it was being presented to “simply be an available option” to some religious groups, he was “not so confident” that it would remain so.
Former Home Secretary, Lord Waddington, said: “without doubt there would be the risk of costly litigation” under the Equality Bill or the Human Rights Act.
And Lord Tebbit said that a clergyman “prepared to register marriages but not to register civil partnerships would be accused of discrimination on grounds of sexual orientation in the provision of services and pressure would be brought to bear on him to pocket his principles and do what he believed to be wrong”.
Speaking to The Daily Telegraph last night, The Christian Institute’s Mike Judge said: “Even if this amendment says on the face of it that it only applies to those who choose to perform civil partnerships, that may not end up being the case and clergy may end up facing very costly legal bills in order to defend themselves against law suits.
“The Government has failed to understand the nature of religious liberty and has treated faith as nothing more than a matter of personal devotion. Now Christians feel let down and ignored. This is another step in the process of trying to force religions groups to abandon their core beliefs.”
Neil Addison, a barrister who speaks out on religious liberty cases, said: “As the law now stands churches and synagogues that are registered to conduct marriages could easily find themselves being sued for discrimination if they do not register to conduct civil partnerships.
“Local authorities could also refuse to grant or renew marriage authorisation to churches and synagogues that do not also apply for civil partnership authorisation.
“The Government should add a new amendment to the Equality Bill to make it crystal clear that there is no legal requirement for religious organisations or officials who perform marriages to perform civil partnerships also.”
But homosexual activists welcomed the move, hinting at further action to compel churches to act against their core beliefs.
Peter Tatchell, an experienced homosexual activist, said: “Our next goal is to secure marriage equality, to end the prohibition on lesbian and gay couples having a civil marriage in a registry office.”
Ben Summerskill, head of the homosexual lobby group, Stonewall, is on record saying the time may soon come when churches will be forced to act against their beliefs.
In November he said: “Right now, faiths shouldn’t be forced to hold civil partnerships, although in ten or 20 years, that may change.”