Even if the American bishops overcome their initial huffiness at being asked to respond at all, and that is not certain, it is difficult to see how they could come up with a response that is both adequate and credible. The liberal tide seems to be running just too strongly. Too many of the American bishops have pledged their allegiance to the pro-gay camp. A lesbian is on the shortlist to be elected as the next bishop of Chicago; Gene Robinson has given the go ahead for clergy in the New Hampshire diocese to conduct same-sex blessings; at least two dioceses are developing official blessing rites.

Moreover, the American bishops have already resoundingly rejected the primates' scheme for pastoral oversight for American conservatives. The Episcopal Church's Presiding Bishop Jefferts Schori is understood to be preparing yet another version that may well prove acceptable to her liberal colleagues, but is highly unlikely to pass muster with the conservatives.

It also appears that there is little room for manoeuvre. Dr Williams himself, in a press conference following the eleventh hour agreement of the communique at the primates' meeting in Tanzania, said it would be 'difficult' if the Americans failed to follow its exact wording. So, if the Americans do fail to respond adequately in New Orleans, it would seem that Rowan will have little choice but to carry out the implicit threat in the communique and withdraw their invitations to Lambeth. Or does it?

The conservatives remain far from confident that this will be the case. There is a growing concern among them that the Archbishop of Canterbury will yet again attempt to play for time by forging another tortuously ambiguous compromise. At last week's consecrations in Kenya and Uganda, at which 10 provinces were represented and eight primates attended in person - a sign that the core group of Global South hardliners may be larger than some believe - all these fears were expressed.

Doubts first began emerging when Lambeth Palace unexpectedly issued invitations in June to all but a handful of bishops for next year's Lambeth Conference. Not only had Rowan invited nearly everyone- albeit with caveats - but he had done so without consultation. Liberals saw this as a sign that Dr Williams had finally jumped into their camp, and was determined to keep the Americans in the Church even if this meant losing Africans and Asians. In contrast, many conservative primates, including those regarded as relatively moderate such as the Primate of the West Indies, Archbishop Drexel Gomez, were dismayed at the lack of consultation. Some also fear that Dr Williams, having issued the invitations, will find it psychologically difficult to withdraw them from liberal American bishops even if they fail to come up to the mark in New Orlea ns.

There has also been confusion about the role of Canon Kenneth Kearon, the secretary general of the Anglican Communion, who appears to have been exercising a growing influence in the absence of Dr Williams on study leave. Conservatives suspect that Canon Kearon, with his experiences of the peace process in Northern Ireland, has reinforced Dr Williams' natural tendency to believe that the crisis can be resolved peacefully if only all the parties can be kept talking long enough.

The hardcore of conservatives, however, want a resolution and they want it now. A number of them are poised to split if nothing clear happens in the wake of New Orlea ns, and the recent consecrations in Africa are a preparatory step for a fully fledged parallel Church if it proves necessary. They have not been reassured by Lambeth Palace's seeming reluctance to call another meeting of all the primates to make a judgment about the outcome of New Orleans.

Dr Williams has said in the past that he will be guided by his fellow primates about how to proceed, but there has been little indication as yet as to how this will be done. Global South primates believe that only a full primates meeting will suffice, even though Dr Williams will be accompanied to New Orleans by members of the primates' standing committee.

Aides to Dr Williams are, however, less convinced of the need for another costly and precipitous summit, and may try to pursue other means of taking soundings. With all these variables up in the air and anxieties swirling like smoke, Dr Williams will not find his return to work this week a comfortable experience.

---Jonathan Petre is the religious correspondent for the Daily Telegraph