King Charles' coronation ceremony could be invalidated because of his affair, a royal author has claimed.
The then Prince of Wales split up with Princess Diana in 1992, with a biography endorsed by Charles saying that by 1986 he and Camilla were already having an affair.
Two years later, in 1994, Charles admitted he had been unfaithful to Diana.
Asked whether he had remained true to her during a documentary about his life he said: “Yes, yes… Until it became irretrievably broken down, us both having tried."
Royal biographer Anthony Holden has now claimed that Charles' confession of adultery could spark a "constitutional crisis".
He wrote in the Guardian : "The Church of England has never crowned a divorced man as King, let alone one who has publicly confessed to adultery – with the relevant woman expecting to be crowned Queen Consort.
"The late Robert Runcie [the former Archbishop of Canterbury] told me this would require a revision of the coronation oath, which would require a new statute of Parliament.
"Given the convention that Parliament does not debate the monarchy without the monarch's consent, this would require the Prime Minister to seek King Charles's permission. This, Runcie told me, would amount to a constitutional crisis."
Experts have since cast doubt over the claims, however.
Sir Vernon Bogdanor, a research professor at King's College London's Centre for British Politics and Government, told the Mail on Sunday: "Charles and Camilla's wedding was followed by a Service of Prayer and Dedication, led by Archbishop Rowan Williams.
'This surely overrides anything Robert Runcie may or may not have said."
Barrister Geoffrey Robertson KC added: "The coronation is a legal irrelevance, just a silly and superstitious Church of England ritual. Charles has no need at all to be crowned by a minority church."
King Charles' historical coronation ceremony is set to take place on Saturday, May 6, and will also see Camilla crowned Queen Consort.
The Palace said the ceremony will be "rooted in longstanding traditions and pageantry" but also "reflect the monarch’s role today and look towards the future".
It is understood that the ceremony will include the same core elements of the traditional service, which has retained a similar structure for more than 1,000 years, while also recognising the spirit of our times.
A Lambeth Palace spokesperson said: "We cannot comment on accounts of a private conversation that Archbishop Robert Runcie may have had while he was Archbishop of Canterbury from 1980-1991.
"But clearly much has changed since that time - both in society and in the Church of England. The current Archbishop of Canterbury, Justin Welby, is looking forward to the great honour of crowning King Charles III and the Queen Consort in May this year.
"Across the Church of England we continue to pray for the King and the Queen Consort as they prepare for this important moment in the life of our nation and the Commonwealth.”
