The Episcopal Church in the US is set to go ahead with the controversial ordination of an openly lesbian bishop.
Saturday's ordination comes despite warnings from the Archbishop of Canterbury that it will deepen an already bitter dispute on sexuality.
Canon Mary Glasspool, 56, will become an assistant bishop in Los Angeles, the first openly gay US bishop since Gene Robinson seven years ago.
Since then the Anglican Communion has been on course for a permanent split.
The election of Mary Glasspool - who has been with her partner Becki for 22 years - represented a snub by the liberal Episcopal Church to other Anglican Churches around the world.
Archbishop of Canterbury Rowan Williams had urged the American Church not to proceed with the ordination, warning that it would further alienate traditionalists who believe active homosexuality to be a sin.
It is likely to accelerate the gradual marginalisation of the Episcopal Church within a two-tier Communion and increase tensions between Anglicans elsewhere.
The Communion has never recovered from the crisis prompted by the election in New Hampshire of Gene Robinson as its first openly gay bishop in November 2003.
The Episcopal Church at first agreed to suspend the creation of gay bishops but reversed that decision last July.