A coalition of conservative Anglican leaders is preparing to create a parallel church for conservatives in America in defiance of the Archbishop of Canterbury, provoking the biggest split in Anglican history.

At least six primates are planning the consecration of a prominent American cleric as a bishop to minister to Americans who have rejected their liberal bishops over the issue of homosexuality, according to sources.

The move will send shockwaves through worldwide Anglicanism and may prove to be a fatal blow to the efforts of Rowan Williams to hold together what he described last month as a “very vulnerable, very fragile” church.

The initiative is understood to have been coordinated by senior African archbishops, including the primate of Kenya, Archbishop Benjamin Nzimbi, who represent the core of the so-called Global South group of conservative primates. But the group has a wider base and is also thought to include several relatively moderate primates from outside Africa.

The size of the group — its leaders represent well over 10 million Anglicans — will alarm Lambeth Palace as it could eventually evolve into a rival Anglican Church.