Justin Welby, the new archbishop of Canterbury, is set to say he is against gay marriage, ahead of a parliamentary vote that is expected to see 180 senior Tories opposing or abstaining.
The archbishop is expected to restate his belief that marriage should be between a man and a woman.
Justin Welby has spoken out ahead of the first parliamentary vote on reforms and is prepared to face questions about the highly divisive issue.
Tories were plunged into deep unrest by proposals that include measures to allow civil partners to convert their partnership to a marriage and enable married people to change their legal gender without ending their union.
The prime minister faces the prospect of some 180 party members, including a significant number of senior figures, opposing or abstaining on the vote. He is expected to attempt to win over MPs today.
Bishop Welby will be formally confirmed in his new role at a ceremony in St Paul’s Cathedral today, and reports in the Daily Telegraph claim he will say that “marriage is between a man and a woman, and always has been”.
Lambeth Palace stressed the view is standard Church of England policy, insisting the archbishop was not planning to wade into the row with a formal statement.
Yesterday Tory activists claimed they felt “a sense of betrayal” at the prime minister’s “bulldozing-through” of reforms, and handed a letter in to No 10 urging a rethink.
Chairman of the Conservative association in Surrey Heath, Geoffrey Vero, has warned the move “may seriously affect David’s opportunity to get re-elected at 2015”.
However, human rights campaigner Peter Tatchell claimed Tory opponents do not represent most Conservative supporters.
“Opposition to equal marriage by some Conservatives is reviving the ‘nasty party’ image and turning off voters. It undermines David Cameron’s attempt to detoxify the Tory brand and present a more caring, compassionate Conservatism.”
Former prime minister Gordon Brown has entered the debate, stating: “I understand the strong feelings in the current debate but I take the view that it is now timely to agree to end another source of discrimination by legalising the right to marriage, and I will support the legislation in the UK parliament and when it comes to the Scottish parliament.”