Anglican leader Rowan Williams has urged bishops to address the deep divisions in the Church at a summit boycotted by a quarter of them over the ordination of gay clergy.

"We must be honest about how deep some of the hurts and difficulties currently are," the spiritual leader of the world's 77 million Anglicans said of the Lambeth conference being staged in the English cathedral city of Canterbury.

Conservatives and liberals have rowed over the ordination of Gene Robinson, the first openly gay bishop in the 450-year history of the Church.

A quarter of the world's bishops boycotted the gathering which began with a bible-reading retreat and then a Sunday service in Canterbury Cathedral before they got down to their working agenda on Monday.

Subjects up for discussion range from the environment to social justice and violence against women.

Archbishop Williams, struggling to avoid schism in a Church where consensus usually rules, had told the bishops on arrival: "It's a great grief that many of our brothers and sisters in the communion have not felt able to be with us."

"We know as we meet that we are also a wounded body," the Archbishop of Canterbury told the bishops at their first plenary session last week before they went into a three-day retreat.

Speaking to the bishops on Sunday before starting two weeks of deliberation, Williams told them: "We stand in the middle of one of the most severe challenges to have faced the Anglican family in its history."

"There is quite properly a sense of being at a deeply significant turning point," he added. "We need renewal and this is the moment for it."

Williams may be hoping to heal wounds but could face one major irritant at Lambeth -- Gene Robinson is coming to Canterbury to attend fringe events and meet bishops informally.

Williams decided not to invite Robinson officially to Lambeth and the U.S. bishop told Reuters before his trip: "I am not making any attempt to attend any session which is for bishops only."

"I am not staging any demonstrations," he said.

Conservative Anglican leaders staged their own conference in Jerusalem last month at which they decided to form a council of bishops to provide an alternative to churches who say they are preaching a "false gospel" of sexual immorality.

The Global Anglican Future Conference (GAFCON) said member churches would continue sponsoring breakaway conservative parishes in the liberal western countries and called for a separate conservative province in North America.