LONDON (Reuters) - A British former minister who quit after failing to shake off claims that he called police "plebs" called for an inquiry on Tuesday after a television programme said he may have been falsely accused and the victim of a dirty tricks campaign.
Prime Minister David Cameron's office said the programme's suggestion that a police officer may have fabricated evidence against Andrew Mitchell was "exceptionally serious" and urged police to investigate the matter urgently.
The disclosures threaten to further undermine relations between politicians and police at a time when the government is cutting force budgets to meet its deficit reduction target.
Mitchell resigned as the "chief whip" in charge of maintaining discipline in Cameron's Conservative party in October after weeks of negative headlines over the alleged insult.
His reported use of the offending word was highly damaging to the ruling Conservatives, reinforcing an image of an elitist government out of touch with ordinary Britons financially squeezed at a time of economic austerity.
Mitchell admitted swearing at police officers outside Cameron's Downing Street offices when told to wheel his bicycle out through a side exit, but denied calling them "plebs", an old-fashioned insult laden with snobbery.
Channel 4 News said previously unseen CCTV footage of Mitchell's confrontation with officers at the security gates raised doubts over the veracity of an account of the incident recorded in a police log and leaked to a newspaper.
It also said there were questions over an email sent to a Conservative lawmaker, supposedly from a member of the public who saw the encounter, after it discovered the sender was a police officer who told the programme he had not actually been there.
The email and leaked logs said several members of the public had overheard and been shocked by Mitchell's alleged outburst. However, the CCTV footage appears to show the street outside the gates almost empty of bystanders.
Mitchell said the email's claims were untrue and "clearly designed to destabilise me".
"It has certainly shaken my life-long support and confidence in the police and I believe now there should be a full inquiry so that we can get to the bottom of this," Mitchell told Channel 4 News.
Cameron's office called on police to urgently establish what had happened. "Any allegations that a serving police officer posed as a member of the public and fabricated evidence against a cabinet minister are exceptionally serious," a Downing Street spokesman said.
The Police Federation, which represents officers, had exploited the "pleb" row in its campaigns against cuts to force budgets and changes to working conditions, but denied on Tuesday it was part of a conspiracy to unseat the minister.
The TV report came after London's police force on Saturday arrested and suspended from duty a police officer over the leaks to newspapers about Mitchell's confrontation.
A police watchdog supervising the investigation said the inquiry was focused on the validity of the officer's claim to a member of parliament that he had witnessed the incident.
The arrested officer, a member of the Diplomatic Protection Group, was not on duty at the time of the incident, the London force said.
(Reporting by Tim Castle; Editing by Stephen Powell)