The “plebgate” row that engulfed Andrew Mitchell was sparked by a police officer who falsely claimed to have witnessed the events, it was said last night.
The officer allegedly wrote to his MP giving details of Mr Mitchell’s behaviour when he was blocked from cycling out of the main gates in Downing Street.
The developments came as Channel 4 News showed previously unreleased footage of Mr Mitchell from the night of the incident in September.
Although there is no sound, the MP can be seen with his bicycle talking to three officers by the main gate before wheels it over to the side gate and leaving,
Mr Mitchell accepts that one of his parting shots to the on-duty officer was: “I thought you guys were supposed to f****** help us.”
However, he denies calling him a “pleb” or a “moron”, insisting parts of a police log of the incident published in the media were “false.”
In his first full interview on the episode, Mr Mitchell demanded a full investigation, saying the episode had shaken his trust in the police.
Mayor of London Boris Johnson said: “These are very serious allegations that must be investigated with all possible urgency.
“An allegation that a serving police officer posed as a member of the public whilst fabricating evidence is a matter of the utmost gravity.”