Christians have appealed to government ministers to block plans to allow gay couples the right to have civil partnership ceremonies in church.

They fear that the proposal will force church leaders to hold civil partnerships and leave them open to legal action if they do not.

The campaign is being organised by anti-gay group Christian Concern for Our Nation (CCFON), which delivered a 6,000-strong petition to Downing Street today against the plan.

It would give faiths the option of holding the ceremonies and would not be compulsory. The Quakers, Unitarian Church and Liberal Judaism have all expressed their wishes to hold the events.

However, Christian traditionalists have seized on a remark made by Stonewall chief executive Ben Summerskill in November.

He told PinkNews.co.uk: “Right now, faiths shouldn’t be forced to hold civil partnerships, although in ten or 20 years, that may change.”

Earlier this month, out gay peer Lord Alli attacked bishops for “misleading” the public over the plan. Some had claimed that churches would be sued for not carrying out ceremonies for gay couples.

Today’s petition said that the government should listen to the “large proportion” of voters who felt the amendment compromises “religious freedom”.

The measure was introduced by Lord Alli as a permissive amendment. He argued that it increased religious freedom, rather than took it away.

Currently, civil partnerships are expressly banned from being held in churches or containing any religious references.

Andrea Minichiello Williams, CCFON director, said in a press release: “Lord Alli’s amendment to the Equality Bill dramatically changes the law on civil partnerships.

“Although it has been presented as an issue of religious freedom, the amendment has the potential to further erode religious liberty in the future.

“The thousands of individuals who have signed the petition asking the government to reject the amendment believe that if it became law, what has been called permissive legislation would ultimately lead to coercing religious believers to act against their conscience.”

Ms Minichiello Williams also tried to use the example of Christian registrar Lillian Ladele as an argument against the amendment.

She said: “This was advanced as ‘permissive legislation’, yet it subsequently has had the effect of forcing registrars to act against their conscience or face dismissal. How long will it be before church ministers are threatened with legal proceedings if they perform marriages between a man and a woman, but not civil partnerships?”

Rebutting earlier claims that the amendment would damage religious freedom, Lord Alli argued that the opposite was the case.

He wrote in the Sunday Telegraph: “Religious freedom means letting the Quakers, the Unitarians and the Liberal Jews host civil partnerships: a decision that they had considered in prayer and decided in conscience.

“But religious freedom also means respecting the decision of the Church of England and the Catholic Church – decisions also made in prayer and taken in conscience – that they do not wish to do so.

“That is what we agreed during the debate, and trying to pretend otherwise is to entirely misrepresent the way which this decision was taken.”