Springfield, USA - Traditionalist Anglicans are to formally announce that they are setting up a new church in the US and Canada.
The move will make the long-discussed split in the Anglican Church in North America a reality.
It means in each country there will be two competing churches, both claiming allegiance to the Anglican Communion.
The American Church's liberal stance on homosexuality has led some traditionalists, including some whole dioceses, to leave the Church.
They have instead formed a range of new alliances, often with Churches in Africa.
On Wednesday those disparate groups are uniting to form a new North American Church.
During a celebration service in Illinois, its leaders will unveil a draft constitution for the new Church.
'Clear procedures'
But doubts remain as to whether or how it will be recognised by the wider Anglican Communion.
The Communion's Secretary General, Canon Kenneth Kearon, has told the BBC that it is entering what he called uncharted waters, and he is calling on the leaders of the new Church to act in accordance with the Communion's existing regulations.
"The issue as I see it is whether in fact this body, or province as they're calling it, wishes to be recognised as a province of the Anglican Communion," he said.
"And I think if they do, there are clear procedures by which that might be explored. And I do urge those involved to address the structures of the Communion."
But those supporting the new North American Church believe that Anglicanism's structures have been unable to safeguard the Church's unity, and they now look to leadership from a group of largely African leaders.
Neither the liberalising American Churches nor this much smaller new Church want to leave the Anglican Communion.
But how they can exist together in the same global communion is looking increasingly problematic.