Williams warns that ill-judged words can lead to suicide or even murder. He cites the homophobic killing last month of David Morley in London. “Any words that could make it easier for someone to attack or abuse a homosexual person are words of which we must repent,” he writes.

The 3-page missive, sent out on Friday night, warns of serious consequences if Anglicans do not heal their rift.

“It is beyond doubt that we stand at a point where the future shape and character of the communion depends on our choices,” writes Williams.

While the archbishop does not state explicitly what his personal views are on the ordination of gays, his letter has been seized on by conservatives as evidence that he supports the liberal wing of the church.

David Banting, national director of Reform, the largest traditionalist group in the Church of England, said: “If somebody who holds orthodox views is by definition thought to be homophobic, that is a very unfair argument. I am simply trying to uphold the faith as we have received it.”

He added: “It (the letter) is presumably a gesture to the gay community who love to peddle this line that they all feel under enormous pressure and they are all being persecuted, which is not true.”

Williams’s leadership of worldwide Anglicanism has been dogged by controversy over homosexuality ever since he was enthroned in Canterbury Cathedral in February 2003.

His inaugural General Synod, held in York last year, was interrupted by Peter Tatchell, the veteran gay rights campaigner who once stormed the pulpit of Canterbury Cathedral during a sermon by Lord Carey, Williams’s predecessor as archbishop.

After taking office, Williams was confronted with the decision of whether to allow Jeffrey John, a gay priest, to be put forward as Bishop of Reading.

Williams gave his consent, but after seeing the furious reaction of conservatives and evangelicals, persuaded John to withdraw, even though this went against his personal convictions. This change of position angered gay rights activists.

The gay bishops row was brought to a head by the election in June last year of Gene Robinson, an openly homosexual candidate, as Bishop of New Hampshire in America.

Twenty-two provinces, mainly in Africa and Asia, have broken relations with the American church over the issue.

A commission set up by Williams in response to the split has proposed a change that would stop provinces taking controversial steps — such as ordaining gay bishops — without agreement of the wider communion.

The most entrenched conservatives include Peter Akinola, Primate of Nigeria, who has called homosexuality an “aberration unknown even in animal relationships”.

Williams’s letter shows his level of concern about the language used by some Anglicans, whom he does not name, towards gays.

He writes: “In the heat of this controversy things have been said about homosexual people that have made many of them, including those who lead celibate lives, feel that there is no good news for them in the church.”

He adds: “Young people are driven to suicide by the conviction that no one will listen to them patiently; many feel condemned not for their behaviour but for their nature.”

Williams, who himself believes homosexuality is compatible with the Christian gospel, shows his anger at Morley’s killing: “As I write these words I have in mind the recent brutal and unprovoked murder of a homosexual man in London by a group of violent and ignorant youths.”

Williams adds that the two sides in the row should not put all the onus on their opponents to apologise. He writes: “Do not think that repentance is always something others are called to, but acknowledge the failings we all share, sinful and struggling disciples as we are.”

Colin Slee, Dean of Southwark, last night called the letter a “very firm slap on the wrist for archbishops and others who have been demonising homosexual people. The archbishop has to reach out and embrace the gay community and I think this letter could be the beginning of that reassurance”.

Additional reporting: Sarah Keenlyside