By Robert Pigott
Religious affairs correspondent, BBC News
Anglican archbishops are meeting in Dar es Salaam in Tanzania, under the chairmanship of the Archbishop of Canterbury, Rowan Williams, in a last-ditch effort to prevent the Communion splitting up over homosexuality.
Much depends on the authority of the Archbishop of Canterbury
One senior theologian reminded Anglicans recently of Jesus' description of the Church: "I am the vine; you are the branches".
The theologian concluded gloomily that it had become clear that the 38 independent churches making up the worldwide Anglican Communion had lost sight of the vine for the branches.
The divisions in the Communion that began with the ordination of a gay bishop by the liberal American branch of Anglicanism, the Episcopal Church, are indeed more entrenched than ever.
On one side are the conservative Anglicans who are adamant that ordaining gay clergy or blessing same-sex relationships in church is a sin, and on the other a coalition led by the Episcopal Church which insists on tolerance and inclusion of homosexual people.
The showdown on the shores of the Indian Ocean has been several years in the making.
After Gene Robinson became Bishop of New Hampshire in 2003, the Communion as a whole - led by its traditionalist majority - produced a "road map" for negotiating the crisis called the Windsor Report.
It demanded an apology from the Americans, a promise not to elect another gay bishop, and an end to same-sex church blessings.
The Episcopal Church met in the summer and came up with a formula which, although it nodded in the direction of these demands, is considered by many traditionalists to have been insufficient to guarantee the Americans a full place in the Communion.
Some are determined to expel the Episcopal Church.
Among the 18 or so generally conservative churches of the developing world (they call themselves the "Global South") is a hardline group of about half a dozen who say they will not even sit down with the Presiding Bishop of the Episcopal Church, Katherine Jefferts-Schori, because of her support for Gene Robinson's ordination.
Divisions began with the ordination of gay bishop Gene Robinson
They have had support from a senior figure in the Church of England, the Bishop of Winchester, Michael Scott-Joynt.
He warned in the Church of England newspaper that if she were present "I am in no doubt that this would destroy the authority of the Communion", going on to claim "the Episcopal Church and its new presiding bishop are increasingly departing from basic Christian belief".
The discussions may be taking place in Tanzania but the real battleground is in America.
Fifty traditionalist congregations have left the Episcopal Church, and many have, in effect, joined conservative churches overseas, and are ministered to by African archbishops.
The hardline churches in Dar es Salaam - they include the churches of Nigeria, Kenya, Uganda and Rwanda - would like official Anglican membership transferred from the Episcopal Church to these dissident congregations.
A lot depends on Archbishop Rowan Williams, his personal authority and his powers of persuasion.
He may even be reduced to shuttling backwards and forwards between rooms containing the various parties at the meeting.
It will also depend on how far the Global South can be split, and its moderate members persuaded to accept a compromise.
Even the best of the probable outcomes will constitute a split in the Communion.
Dr Williams would be doing well to create a two-tier Communion, with full membership reserved for those "orthodox" churches who sign up to the Windsor Report's traditionalist view of sexuality - in essence that sexual intercourse should be reserved for heterosexual marriage.
Looser, associate, membership would go to those who could not in good conscience put their names to such a document.
Perhaps over many decades, perhaps even centuries, the two tiers could be reconciled.
The traditionalist American congregations might be accorded full membership of the Communion.
But there are potentially plenty of bleaker outcomes, especially if archbishops walk out of the meeting.
The Episcopal Church, which is relatively rich, and guards its independence jealously, would not be alone should it strike out alone.
Other liberal churches, including Canada, Mexico, Brazil and New Zealand, might join it.
But perhaps more likely, members of the Global South might set up their own parallel church.
Even if the main purpose were to provide a home for traditionalist Americans, such an "alternative Communion" would eventually attract conservative evangelical congregations from churches throughout the world, opening the way for splits even in the Church of England itself.
It would represent the historic schism towards which the branches of the Anglican vine seem to have been moving so inexorably.