Tony Blair personally sanctioned the controversial appointment of a gay priest to one of the most important Church of England jobs as part of a Downing Street campaign to warn Anglican leaders that a person's sexuality should not bar them from senior positions.
Number 10 officials are understood to have been dismayed by recent Church infighting over homosexual clergy. They believe the Church is in danger of being seen to be out of step with modern society.
However, Downing Street's ground-breaking decision to install the openly gay but celibate Canon of Southwark, Jeffrey John, as Dean of St Albans in Hertfordshire plunged the Church into a fresh crisis last night.
John's promotion, recommended by the Prime Minister's appointments secretary, William Chapman - and endorsed by Blair - will also raise questions over the extent to which politicians should decide who fills senior ecclesiastical positions.
It is understood that Chapman had been trying to secure a senior job for John since last October and considered a number of vacancies.
The simmering row between Anglican conservatives and liberals boiled over last year when the Archbishop of Canterbury, Rowan Williams, blocked John's appointment as Bishop of Reading - a decision seen as a victory for hardline conservatives. But the subsequent election of American Gene Robinson, who lives with a long-term male partner, as Bishop of New Hampshire reignited the debate.
In contrast to the way bishops are chosen, Number 10 wields almost total control over the appointment of deans. Chapman is understood to have taken soundings from Church leaders but was adamant that John, seen by many as one of the most brilliant theologians of his generation, should be given a senior position.
Religious groups quickly pointed the finger at the crucial role played by Downing Street over John's job. 'This is Number 10 saying the way the Church treated Jeffrey John over the Reading affair was poor,' said Martin Reynolds, spokesman for the Lesbian and Gay Christian Movement.
Liberals in the St Albans diocese are said to have lobbied for months for John to replace the Very Reverend Christopher Lewis, who moved to Christ Church, Oxford, last October.
The decision will outrage senior Anglican leaders on both sides of the debate who had hoped the issue would be left alone while a Church commission carries out an extensive consultation exercise due to report until next year.
A number of dioceses across the globe opposed to homosexual clergy have already threatened to break away, and John's appointment will add to a sense that the Church is now in a crisis beyond Williams's control.
African archbishops intensified the threat on Friday by insisting that the US Episcopal Church, which elected Robinson as bishop, must be disciplined within three months unless 'it repented'.
Yesterday conservative groups, who believe homosexuality is a sin, attacked Blair's decision. David Virtue, the evangelical commentator, said: 'This is an outrageous appointment. It is a backdoor attempt to make homosexuality mainstream in the Church of England.'
Downing Street, due to make the announcement on Tuesday, would not comment.