PRINCES William and Harry have invited the Archbishop of Canterbury to compose a special prayer in memory of their mother to be said at this month’s memorial service to mark the 10th anniversary of her death.

Rowan Williams’s prayer for Diana, Princess of Wales, is also likely to be circulated to Anglican parishes around the country to mark the anniversary on August 31.

Mourners at the service, which will be shown on BBC1, will be led by the Queen and other senior members of the royal family. Gordon Brown and his two predecessors as prime minister - Tony Blair and Sir John Major - are also expected to be present at the Guards Chapel in Wellington Barracks, London.

The prayer is expected to reflect Williams’s strong feelings about the death of Diana. Writing shortly after her fatal car crash, he described the response from the public as “a potent lament for a lost sacredness, a magical and highly personal but equally a ritualised focus for public loyalty”.

He added: “The images of her had consolidated her ‘iconic’ status . . . Her death produced an utterly expected outpouring of charity-related activity, egalitarian rituals to purge unmanageable emotion.” The guest list for the service has already led to acrimony. Critics have said that the Duchess of Cornwall should stay away because of her relationship with the Prince of Wales while the princess was still alive. This led the princess to say in a televised interview in 1995 that there were “three of us in this marriage”.

Camilla has told friends she believes it is her “duty” to attend, but one said: “The prince should let her stay away - a sudden bad back on the day would be very useful.”

There has also been criticism of the decision to exclude four long-serving members of Diana’s personal staff - Paul Burrell, her butler; Patrick Jephson, a former private secretary; Ken Wharfe, who worked as her protection officer; and Victoria Mendham, her personal assistant for eight years. The first three have written about life with the princess, which William and Harry regard as breach of trust.

Some of Diana’s friends have criticised her sons’ decision to invite Richard Chartres, Bishop of London, to give the address at the service. Chartres, an executor of the princess’s will, was accused by parents of some of her godchildren of failing to guard their interests.

The princes will read lessons at the service, which will be conducted by Patrick Irwin, padre of the household division. It will include the princess’s favourite hymn, I Vow to Thee My Country.