But the Daily Mirror says Mr Burrell's story in his own words will be "frank, searing stuff".

Mr Burrell told the paper his story would be "the truth, the whole truth and nothing but the truth".

"With this story I have scores to settle," he said.

"I always knew the court case was to going to have enormous implications. I just never realised it was going to be a moment of history."

Mirror editor Piers Morgan told the BBC members of the Royal Family and the Spencer family could be embarrassed by the revelations.

However the Mirror editorial admits it is not expecting Mr Burrell "to reveal the most sensitive and damaging of his secrets" given his loyalty to Diana during her life and after her death.

The Mirror editor denied the story would distress princes William and Harry.

Queen's role

Media lawyer Mark Stephens told BBC News it was a story worth "many millions" and said: "Piers Morgan and the Mirror have really got a scoop and a steal."

He added he thought the story would probably provide the former butler's perspective on facts already in the public domain, and not betray any confidences.

We have almost reached game show proportions, phone a friend

Tony Lloyd, Labour MP

The collapse of Mr Burrell's trial has sparked a heated debate with calls for an independent inquiry and constitutional reform.

Prime Minister Tony Blair defended the Queen's role in bringing to light evidence that acquitted Mr Burrell, saying she had acted "entirely properly".

Labour MPs have demanded to know why the Queen delayed intervening and have demanded she pay the costs of the �1.5m trial.

Tony Lloyd, the Labour MP for Manchester Central, said he wanted to see an independent inquiry.

Bizarre

He told BBC Radio 4's Today programme: "We have almost reached game show proportions, phone a friend... this is bizarre.

"Really the police do have to answer questions as to how a trial got as far as it did costing �1.5m."

Lord Harris, chairman of the Metropolitan Police Authority, said he it was difficult to see what could be learned from the trial.

He told the programme: "What we have said to the commissioner is that he should report to the police authority if there are any matters or any lessons he feels that operationally need to be learnt from it."