Britain’s most senior police officer promised a “ruthless” investigation into an alleged conspiracy against a Cabinet minister “no matter where the truth takes us”.
Met Police Commissioner Bernard Hogan-Howe defended his handling of the Andrew Mitchell “plebgate” row after breaking off from his holiday to be briefed on progress.
Mr Mitchell increased pressure on the force yesterday when he claimed he was the victim of a deliberate attempt to “toxify” the Tories and ruin his career.
The former chief whip was forced to quit his Cabinet post amid a storm of protest – fuelled by the Police Federation – over claims he called officers “plebs” during an altercation in Downing Street.
But last week Scotland Yard opened an investigation into a possible conspiracy against the MP after it emerged an email from a civilian witness backing up the claims was in fact written by another officer.
In a statement, Mr Hogan-Howe said: “The allegations in relation to this case are extremely serious.
“For the avoidance of doubt, I am determined there will be a ruthless search for the truth – no matter where the truth takes us.”
He said the force’s determination to get to the truth was proved by his decision to devote 30 officers to the task and the arrest of a member of the diplomatic protection squad and a civilian.
“I believe these actions are vital in maintaining public confidence in the police,” he said.
Mr Hogan-Howe has faced criticism of his handling of the case after saying earlier this week that, despite the arrest of the officer, he had seen no evidence that “really affected the original account of the officers at the scene”.
Deputy Assistant Commissioner Patricia Gallan, head of Professional Standards, is to head the investigation, supervised by the Independent Police Complaints Commission.
The Commissioner will be grilled on the case when he appears before MPs on the Commons Home Affairs Committee next month.
The Diplomatic Protection Group officer was arrested on December 14 on suspicion of misconduct in public office over the email sent to Tory MP John Randall, the deputy chief whip.
It largely backed up the account of what happened in the official log – subsequently leaked to a national newspaper – that claimed Mr Mitchell called officers “plebs” and “morons” during a foul-mouthed tirade.
The politician admits swearing during the exchange but firmly denies using the word which came to symbolise the controversy which eventually forced him out of office.
CCTV footage from the street, which Mr Mitchell only saw after he was forced to resign and was broadcast by Channel 4 last week, appears to contradict some elements of those accounts such as the presence of public witnesses.
On Thursday, police arrested and questioned a 23-year-old man on suspicion of intentionally encouraging or assisting the commission of an indictable offence on December 14. Mr Mitchell spoke out in the Sunday Telegraph as he intensified efforts to clear his name and pave the way for a return to the Government’s ranks two months after being forced out. “These awful toxic phrases which were hung round my neck for weeks in a sustained attempt to toxify the Conservative Party and destroy my career were...totally untrue,” he said.
He is particularly angry with the Police Federation, which represents rank-and-file officers, whose local branches organised protests by members wearing “PC Pleb” T-shirts and demanded Mr Mitchell’s sacking.
Tory former policing minister Nick Herbert called for action to tackle a “cancer” of corruption within the police.