The Archbishop of Canterbury, Dr Rowan Williams, is to celebrate a “secret” communion service for gay clergy and their partners in London.

Dr Williams will celebrate the eucharist at St Peter’s, Eaton Square, the Church of England parish known as a home to the country’s liberal and wealthy Anglican elite. Dr Williams will also give an address titled: “Present realities and future possibilities for lesbians and gay men in the Church.”

The event has been organised under the “Chatham House Rule” which prevents any disclosure of the discussions there or even when and where it is taking place. It takes place at 10am on 29 November.

Dr Williams has asked to know who will be present. Names will be on a list which will be shown to the Archbishop only and the list will be shredded once seen by Dr Williams. Among those attending will be convenor Chris Newlands, chaplain to the Bishop of Chelmsford, the Right Rev John Gladwin.

Also present will be the Vicar of St Peter’s, the Rev Nicholas Papadopulos, former chaplain to the Bishop of Salisbury, the Right Rev David Stancliffe. Dr Williams’ mission to maintain the unity of the Anglican Communion, rent with schism since the 2003 ordination of the openly-gay Bishop Gene Robinsonm, has never appeared less likely to succeed.

The disclosure of the event could not have come at a time more likey to destabilise him. Later this week he is due to attend a meeting of US Episcopal bishops to discuss the crisis. He has returned from three months on holiday and sabbatical, when he has been working on an important study of the Russian writer Dostoevsky, to be greeted by a Church in perilous disarray.

African Archbishops from the Global South group of churches have been consecrating like-minded evangelical bishops from the US to pastor parishes alienated by The Episcopal Church’s liberal drift. A new structure is in place to facilitate a breakaway province in the US. There is speculation that at least one African province could be close to consecrating a missionary bishop in England.