The government has headed off moves to annul or delay regulations allowing religious groups to hold civil partnership services on their premises.
An amendment tabled by Conservative peers that would have forced ministers to reconsider and redraft the regulations, which came into force on 5 December, was dropped after a Home Office minister in the Lords gave repeated assurances that no religious group or individual clergy would be forced to act against their consciences to hold the ceremonies.
Some liberal religious organisations, including the Quakers, Unitarians and liberal Jewish synagogues, have said they hope to conduct partnership services, though the main denominations have ruled them out.
Conservative peers and evangelical campaigners have claimed that people wanting civil partnerships might bring legal actions against church authorities under the Human Rights Act or that local authorities could force churches to hold civil partnerships as a condition of licensing heterosexual weddings.
But the Church of England's lawyers and Roman Catholic bishops believe the legislation contains adequate safeguards.
Lady O'Cathain, who has led the opposition, claimed the regulations were fatally flawed and put religious freedom in jeopardy. "We cannot put churches in the legal firing line and sort it out later," she said, adding that she had received "obnoxious" letters, and insisting that she did not oppose civil partnerships or gay people but said:.
But lawyer peers, including those specialising in human rights law, insisted that religious freedom, far from being put in jeopardy, was safeguarded because the legislation was permissive and did not force religious organisations to conduct civil partnerships.
They repeatedly pointed to a clause in the equality act which states: "For the avoidance of doubt, nothing in this act places an obligation on religious organisations to host civil partnerships if they do not wish to do so."
Lord Carlile, a Lib Dem lawyer, said: "The idea that those words somehow create a doubt – what could be more illogical than that?"
His colleague Lord Lester, a human rights lawyer, said there was "not a snowball's chance in hell" that any bid to force churches to act against their will would succeed.
"No respectable member of the bar would be likely to say otherwise. They would have to find the funds to fight the action themselves and they would fail in the court, the court of appeal and the supreme court."
Only the former Conservative lord chancellor Lord Mackay, who is a member of the Free Presbyterian Church of Scotland, expressed reservations, calling for an amendment that would emphasise that churches would be exempt from legal challenges brought under any legislation.
Church of England bishops attending the Lords were themselves divided: the Rt. Rev John Pritchard, Bishop of Oxford supported the regulations, while the Rt. Rev. Nicholas Reade of Blackburn opposed: "At the end of the day clergy should not be put at risk of having to defend such claims even if they seem unlikely and the prospect of success remote," he said.
Lord Henley, Home Office minister of state, told peers: "There is no obligation. It would be a very, very vexatious litigant who would bring an action and I don't think they would stand much chance in the courts."
He promised that the government would keep the legislation under review, and with that assurance O'Cathain withdrew her amendment.