The Queen's anger was not simply in response to what was seen by many as a snub to the rest of the Royal Family but also the fact that the Princess had rejected the Queen's and the Prince of Wales's terms for her uncomfortable existence within the monarchy.
"Economically and financially, everything has been agreed," said one source. "But the sides cannot agree on Diana's role and her title."
It is understood this was behind the Princess's decision not to join the rest of the family for Christmas. "She didn't want to go while there were still things unsettled," said the source.
A friend of the Princess confirmed that cancellation of the Sandringham trip precipitated the Queen's action but he said the decision was based on suspicion that divorce moves were afoot. In particular, the Prime Minister's meeting with her on Wednesday night was arranged a week in advance. It is thought she may have believed John Major was planning to break some news to her and she did not want to be "ambushed" by the family at Christmas.
The Princess decided on Sunday not to go to Sandringham and telephoned her decision to the Palace. It is understood the Queen was deeply unhappy and within hours had prepared letters for the Prince and Princess which were delivered on Monday. The Queen expressed "anger and frustration" and urged a divorce as soon as possible. Soon afterwards, Prince Charles sent letters agreeing to the proposal.
The Queen's reaction was said by some to have been a "knee-jerk" response. Harold Brooks-Baker, publisher of Burke's Peerage, said: "Everyone was expecting an announcement before Christmas about the marriage of Prince Edward to Sophie Rhys-Jones. That would seem impossible after this and it does point to a snap decision by the Queen being responsible."
Divorce has seemed inevitable since the Princess's appearance on BBC1's Panorama last month in which she confessed to an affair with James Hewitt.Reuse content