In a long-anticipated Advent message to the 38 primates of the communion, the Very Rev Rowan Williams criticised African and other church leaders who have consecrated their own American bishops and offered to look after the small number of dioceses whose conservative American bishops have said they wish to separate from the US church and seek oversight from foreign provinces.

In a rebuke to conservatives who claim theirs is the true and only voice of authentic Anglican identity, Williams said: "Not everyone carrying the name of Anglican can claim to speak authentically for the identity we share as a global fellowship ... a great deal of the language that is around in the communion at present seems to presuppose that any change from our current deadlock is impossible, that division is unavoidable and that such division represents so radical a difference in fundamental faith that no recognition and future co-operation can be imagined. I cannot accept these assumptions and I do not believe as Christians we should see them as beyond challenge."

The detailed statement is likely to infuriate conservative Anglican pressure groups, who have been demanding that the church should discipline or expel the Americans for electing the Right Rev Gene Robinson, the openly gay bishop of New Hampshire, in 2003. The archbishop met all the US bishops in New Orleans in September when they formulated a statement agreeing not to endorse any further gay bishops or to authorise formal blessings services for same sex couples.

His silence since that meeting has created a vacuum which has exasperated liberals and conservatives anxious for him to give a lead. Williams put forward two proposals to keep the American church in the Anglican communion: "professionally facilitated conversations" between US leaders and their critics to try to achieve better mutual understanding, reduce tensions and clarify options, and setting up a group of primates to produce proposals to put to next year's Lambeth conference on the issues that the gay crisis has thrown up. Neither last night seemed likely to satisfy the church's conservatives.