The rector of one of London’s oldest churches has defied his bishop to “marry” two gay priests in a traditional ceremony.

The Rev Martin Dudley officiated last month before a congregation of 300 as a favour to friends. However, he did not inform the Bishop of London, Richard Chartres.

A Church of England spokesman said last night that it was a “fairly serious” breach of the House of Bishops’ strict guidance on same-sex ceremonies.

The Rev Peter Cowell, 50, and the Rev David Lord walked down the aisle at the 12th-century St Bartholomew the Great Church, in the City of London, which appeared in Four Weddings and a Funeral.

Both Cowell, an honorary vicar at Westminster Abbey, and chaplain at St Bartholomew’s hospital, and Lord, an Anglican priest from New Zealand, wore morning suits. The service was a blessing of their civil partnership. The liturgy was based on the Book of Common Prayer. Following hymns, readings from the Bible and Shakespeare, the couple exchanged vows and rings before taking communion.

Dudley said last night: “Unrepentant would be the right word. I have made no secret about this. I have done something that was a very nice pastoral, godly occasion. There were 300 people at the service, and 200 communicants. At least a tenth were clergy.”

Dudley added that he had asked the bishop for guidance when he was first requested to bless the union of his church treasurer two years ago. The bishop replied that he would be grateful if the service was not offered.

“I have never offered this service,” said Dudley. “If you visit the church you will find nothing that says civil partnerships will be blessed, but when I am asked by friends to bless them what do I say?

“I certainly didn’t do it to defy anyone. I have done what I believe is right.” He added that he was not expecting any reprimand.