He wants them not only to acknowledge the rift but effectively formalise it by scaling the Anglican Communion back into a loosely linked organisation -- a step aides liken to "moving into separate bedrooms" rather than full-scale divorce.

But he is understood to fear that the confrontation will trigger an angry walk-out by traditionalist archbishops, particularly from Africa, which in turn could lead to "large chunks" of the Church of England itself breaking away.

Equally, he has infuriated the liberal-leaning American branch of the church -- whose decision to ordain the first openly-gay bishop, Gene Robinson, in 2003 led to the rift in global Anglicanism -- by inviting the breakaway traditionalist Anglican Church of North America (ACNA) to the meeting even though it is not officially part of the Anglican Communion.

Aides to the Archbishop said he is now convinced that, after more than a decade of open hostility, the rift between different wings of what is the world's third largest church must be resolved.

"We've actually got to draw a line here, we can't go on," said one Lambeth Palace source.

"Justin can't leave his successor - whoever she or he may be - to inherit this situation in which you spend vast chunks of time trying to placate people and keep them in the boat without ever getting the oars out and starting to row."

It is understood that the Archbishop accepts that there is at least a 70 per cent chance the strategy will fail in some way and a one in three chance of the meeting ending in disaster and triggering a permanent schism.

"If that happens, the whole thing goes completely pear-shaped, it will pull apart large chunks of the Church of England, fairly quickly particularly the more conservative elements," one aide added.

"It is high risk because loads of people will be trying to stop this happening ...but the view that Justin has come to is that we've got to start treating people as adults which means that if they choose not to come he says fine that's your choice, we are not going around grovelling and trying to just tweak everything to make it happen.

"It is time we stopped messing around with internal rows.

"As the third largest global Communion, or denomination, it would be nice if we did something useful for a change."

One idea being considered is to effectively dissolve the Anglican Communion as it currently exists -- in which 38 national churches, or provinces, are formally linked to each other -- to a slimmed-down structure in which they are all tied to the "mother church" in Canterbury even if, in some cases, they have no communication with each other.

Lambeth Palace sources said the idea is that each church would have enough "wriggle room" to hold different positions on questions like gay marriage without breaking up the wider Anglican "family".

"It's not quite a legal separation, if one is going to pursue that metaphor I think it's more moving into separate bedrooms," one source explained.

The Archbishop signalled last year that there might not be another Lambeth Conference -- the once-in-a-decade gathering of Anglican bishops from around the world -- because of the split.

When the last time one was held, in 2008, hundreds of traditionalists boycotted the event and staged their own gathering in Jerusalem known as "Gafcon" (the Global Anglican Future Conference) which became a permanent movement - now seen by some as a rival centre of power within Anglicanism.

But Archbishop Welby is now said to be determined to press ahead with a full Lambeth Conference, possibly in 2020.

One aide remarked: "Actually there is going to be one, we are still finalising the dates but if so few people come that we have it in a telephone box then we have it in a telephone box."

He added that the talks in January were being viewed as a "last throw of the dice" to save the Anglican Communion.

"Could well be, I don't think we'd want to hide that, we wouldn't want to pretend," the aide added.

"Justin is nerving himself to consider it as that and I think that has been one of the more difficult parts of the last six months because actually he is profoundly committed to the future of the Anglican Communion and to the vision of what it could be and ought to be under God in this world as a bridge builder and he thinks it would be a tragedy if that didn't happen - but you can only do what you can do."

Announcing his plan, the Archbishop said: "I have suggested to all Primates that we need to consider recent developments but also look afresh at our ways of working as a Communion and especially as Primates, paying proper attention to developments in the past."

He added: "The difference between our societies and cultures, as well as the speed of cultural change in much of the global north, tempts us to divide as Christians: when the command of scripture, the prayer of Jesus, the tradition of the church and our theological understanding urges unity.

"A 21st-century Anglican family must have space for deep disagreement, and even mutual criticism, so long as we are faithful to the revelation of Jesus Christ, together.

"We have no Anglican Pope. Our authority as a church is dispersed, and is ultimately found in Scripture, properly interpreted. In that light I long for us to meet together under the guidance of the Holy Spirit and to seek to find a way of enabling ourselves to set a course which permits us to focus on serving and loving each other, and above all on the proclamation of the good news of Jesus Christ."