The heads of the Anglican Church have expressed "very great concern" over the church marriage of two gay priests which observers are speculating could contribute to a split the worldwide Anglican Church.

New Zealander Dr David Lord and his partner Peter Cowell, both Anglican priests, were married recently at the historic St Bartholomew the Great Church in London, exchanging vows and rings in the presence of a congregation of bridesmaids and best men. The ceremony was presided over by a third priest.

Lord is believed to now be in the city he was brought up in, Hamilton, and there is media speculation that Cowell is soon to join him.

The Anglican Church has for years wrestled with pressure from within to liberalise its stance on homosexuality. The Archbishop of Canterbury, Dr Rowan Williams, in a joint statement with the Archbishop of York, Dr John Sentamu, said clergy who disagree with the Church's teaching "are at liberty to seek to persuade others [but they are] not at liberty simply to disregard it."

Although the ceremony was conducted a month ago, it was only made public late last week, in what some see as an attempt to fan the flames of an increasingly bitter row over homosexuality in the lead-up to next month's Lambeth Conference.

The Conference, held every ten years and attended by Anglican hierarchy from around the world, has already been rocked by the gay issue with conservative African bishops threatening to boycott it if the openly gay American Bishop Gene Robinson was invited. Archbishop of Canterbury Williams buckled to the pressure and did not invite Robinson, who will attend only one session of the conference in a private capacity.