The Church of Nigeria gave its strongest indication yet on Monday that it would boycott next year's conference of global Anglicans to protest against what it called "intransigence" by pro-gay US and Canadian churches.

American liberals and conservatives from Africa, Asia and Latin America have been locked in a battle for the soul of the 77-million strong Anglican Communion for over a decade.

The dispute over the ordination of gay bishops and blessing of gay marriages is threatening to create a schism ahead of next year's Lambeth Conference, a meeting of more than 800 bishops which is meant to cement the global communion once a decade.

At a meeting in Tanzania in February, conservative bishops gave American and Canadian churches until September to declare a moratorium on ordaining gay clergy and blessing same-sex unions.

Seven weeks before the end of the deadline, Nigeria's Peter Akinola, who leads the conservative "Global South" representing at least a third of global Anglicans, said hopes for a unified communion were as dim as ever.

"The consequence is most serious because, even if only one province chooses not to attend, the Lambeth Conference effectively ceases to be an instrument of unity," Archbishop Akinola said in a statement on the Church of Nigeria website.

Some church leaders, including the Archbishop of York, have warned conservatives that they will effectively expel themselves from the Anglican Communion if they do not attend the conference, expected to be held in July 2008.

With 17.5 million members, Nigeria is the second-largest Anglican province after the Church of England, which has 26 million, but its number of regular churchgoers is far higher and growing.

"Repentance and reversal by these provinces may yet save our communion. Failure to recognise the gravity of this moment will have devastating impact," said Nigeria's 63-year-old primate.

The worldwide Anglican Communion has been sharply divided since 2003 when the 2.4 million-strong US Episcopal Church consecrated Gene Robinson as the first openly gay bishop.

Archbishop Akinola in May consecrated dissident Episcopal priest Martyn Minns as bishop of a new Nigerian church in the United States.

Archbishops in Kenya and Uganda plan to consecrate three priests as bishops for breakaway orthodox congregations in the United States in the coming weeks, creating more conservative outposts opposed to the liberal American mainstream.

African bishops say they want to rescue the US churches and individuals who might otherwise abandon Anglicanism. Liberals say Africans are violating church rules by setting up fiefdoms in the United States.

The Archbishop of Canterbury Dr Rowan Williams, who leads the worldwide communion, is struggling to avoid a full-blown schism and has appealed to African primates to stop the consecrations.