Former Cabinet minister Andrew Mitchell has lodged a formal complaint against Scotland Yard over the apparent leaking of its report into the “Plebgate” affair.
The senior Tory MP has written to the Independent Police Complaints Commission (IPCC) accusing the Metropolitan Police of a continued campaign to “destroy” his career.
Mr Mitchell took the action after newspaper reports suggested a police file passed to the Crown Prosecution Service contained no evidence that officers lied about his behaviour.
He strongly denies calling officers “plebs” during an altercation over their refusal to allow him to ride his bike through the Downing Street gates last year.
The politician – who quit as chief whip amid the storm over the incident – claims he is the victim of a conspiracy by officers to “toxify” the Tories and blacken his name.
In a letter to IPCC deputy chairman Deborah Glass, he wrote: “We are deeply dismayed that the Metropolitan Police appear to have leaked part of their report prepared for the Crown Prosecution Service to certain members of the press and spun it to the advantage of the police officers involved.
“This was an enquiry into a dishonest and illicit attempt to blacken my name and destroy my career. It would appear that this police enquiry continues precisely that process.”
Keith Vaz, Labour chairman of the Commons home affairs committee, said the latest development showed it was wrong for Scotland Yard to lead the inquiry into its own officers and called for the whole investigation to be taken over by the IPCC.
Scotland Yard is investigating how the Sun and Daily Telegraph obtained information about the “Plebgate” row and if the details came from police.
Three officers from the diplomatic protection group have so far been arrested as part of the investigation. All three remain suspended.
Britain’s most senior police officer had promised a “ruthless” investigation into the alleged conspiracy “no matter where the truth takes us”.
The inquiry is being supervised by the IPCC and the commissioner invited the Greater Manchester force to provide an external review.
A spokesman for the newspaper said it stood by its story “and will defend this claim vigorously”.
Conservative Party chairman Grant Shapps said: “Clearly he [Mr Mitchell] feels something went terribly wrong.
“There have been four arrests so clearly the police are taking this seriously.”