Rowan Williams, the Archbishop of Canterbury, is set to reignite the ferocious row surrounding the appointment of an openly gay man as an Anglican bishop in the United States - by arguing that it defies the Church's established position.
Williams is expected to tell Church leaders meeting in London on the divisive issue that the impending consecration of Canon Gene Robinson - an openly gay man with a long-term partner - as Bishop of New Hampshire is in breach of the Church's position on homosexuality as set out in 1998.
Williams, spiritual head of the 70 million-strong global Anglican community, will dismay modernisers who had hoped he would encourage a more liberal agenda than his predecessor, George Carey.
'People think Rowan is a liberal, but he's much more complicated. He proved he would take action to preserve the unity of the Anglican Church over the Jeffrey John affair and he will do so again this week,' said one senior cleric.
Canon John, who is homosexual but celibate, was appointed Bishop of Reading earlier this year. The move prompted a fierce backlash from the orthodox wing of the Church and, following meetings with Williams, John resigned.
Liberals said the conservatives used John's appointment to attack Williams and send a warning shot that they were not prepared to give in to modernisers. 'Rowan Williams was the target and Jeffrey John was the victim,' said Colin Slee, Dean of Southwark Cathedral and a staunch supporter of John.
'Ecusa (the US council that voted for Robinson) are in error,' said Dr Philip Giddings, a critic of Canon John's appointment. 'The conference needs to address this, to deal with the error, offer a warning and, if there is no satisfactory response, suspend them from the instruments of communion.'
Earlier this month Williams hinted at the way he was thinking when he told the Vatican radio station that he would be 'very surprised indeed' if his Church's position on the ordination of homosexuals had changed by the end of the conference.