It also led to yet another angry public broadside from Mohamed al-Fayed, owner of the hotel and of Harrods.
Sir Robin's letter said: 'Dear Peter We sucked this orange dry in our correspondence earlier in the year. For the record I do not regard Jonathan Aitken as having lied to me or misled me.
At the time of your correspondence with me and the Prime Minister's office, Mr Aitken gave me a complete copy of the letter from Mr Klein together with other documentation relating to his bill at the Ritz Hotel.
I am satisfied that, despite the discrepancies in the billing to which you have devoted so much attention, Mr Aitken and his wife paid their bill at the Ritz in full.
Yours sincerely Robin Butler'
The statement from Mohamed al-Fayed, after he had watched Prime Minister's questions on television, said: 'I note with interest that Mr Aitken is maintaining that he and his wife settled his bill at L'Hotel Ritz - she was not a guest. I note with interest that the Secretary of the Cabinet has accepted his explanation in spite of the fact that his whole bill was put onto the account of a Saudi businessman.
I am surprised that the Cabinet Secretary has reached his decision without reference to me. I would have been able to help him in his deliberations.
This is the second time in less than a week that I have not been asked for factual information on matters being determined by the Cabinet Secretary and reported to the Prime Minister. I listened to the call by the Leader of the Opposition for an open investigation into all relevant matters. I should be very happy to cooperate with such an investigation as long as it is conducted by someone of the calibre of Lord Justice Scott.
Of course, that presumes that I would be asked to do so.'