The Archbishops of Canterbury and York have written to Prime Minister Tony Blair in support of an exemption from anti-discrimination legislation for Roman Catholic adoption agencies.

In the letter the Archbishops, the most senior clergy in the Church of England, tell Mr Blair that, “the rights of conscience cannot be made subject to legislation, however well meaning.”

Their intervention in support of Cardinal Cormac Murphy-O’Connor’s position that Catholic adoption agencies would rather close than consider gay couples as candidates for adoption is the first time the Anglican leadership have taken a public position on the ongoing row.

Archbishop of Canterbury Rowan Williams and the Archbishop of York John Sentamu pointed out to the Prime Minister that there are already exemptions in the provision of services on the grounds of conscience or belief, such as the right of doctors working for the NHS to refuse to perform abortions.

They also attacked the treatment of Communities Secretary Ruth Kelly, who has been subject to resignation calls because of a perceived clash between her personal beliefs as a Roman Catholic and her governmental responsibilities as Minister for Equality.

Ms Kelly delayed the introduction of the Sexual Orientation Regulations after a thousands of people made submissions about the new rules to her department.

“It would be deeply regrettable if … a climate were to be created in which some feel free to argue that members of the government are not fit to hold public office on the grounds of their faith affiliation.

“This is hardly evidence of a balanced and reasonable public debate,” the Archbishops said in their letter.

On BBC Radio 4’s Today programme this morning, Archbishop Sentamu clarified his position on homosexuality.

“The Church of England is very clear that sexual orientation is not sinful.

“What the Church then goes on to say that homosexual … acts actually fall short of the glory of God, like adultery and fornication and they require repentance.”

On BBC’s Newsnight last night, the Roman Catholic Bishop of Birmingham conceded that agencies controlled by the Church already place children with single gay people, but only in circumstances where it is in the best interests of the child.

MP Angela Eagle, also appearing on the programme, repeated the point she made to PinkNews.co.uk earlier in the week, that by definition there cannot be equality legislation that has exemptions.

The Lord Chancellor, Lord Falconer, has also said that he cannot see how an exemption could work.

A Downing St spokesman said that the Prime Minister has taken charge of finding a way through the current impasse, with one possible compromise being a phased introduction of the new rules for Catholic adoption agencies.