A police officer who claimed in a drunken rage to have witnessed the Plebgate row was jailed for 12 months today for misconduct in a public office.
Pc Keith Wallis, 53, of West Drayton, west London, sent an email to Conservative deputy chief whip John Randall, who was his MP, wrongly claiming that he had seen what happened as Andrew Mitchell left Downing Street on September 19, 2012.
Mr Mitchell, then chief whip, had been involved in a heated confrontation with another police officer, Toby Rowland, after he was refused permission to cycle through the main gate.
Wallis, who worked at Metropolitan Police diplomatic protection group, was moved to act by "rumour and gossip" about the incident in which Mr Mitchell was accused of calling the officer a "Pleb".
Emotions were already running high following the killing of two female officers, Pc Fiona Bone and Pc Nicola Hughes, in Manchester the day before, the Old Bailey was told.
The officer, who was just one year from retirement after a 30-year career, was also intoxicated and suffering from mental illness at the time, the court was told.
Following a month of intense media interest in the story, Mr Mitchell, who always denied using the word "Pleb", was forced to resign his post.
Defending, Patrick Gibbs QC appealed for leniency for Wallis who had admitted the off ence.
He said Wallis was in no way part of a conspiracy against Mr Mitchell and there was no attempt to pervert the course of justice.
He said: "He would be the ideal scapegoat for more sophisticated men but sending him to prison would be to mistake this for what it is not."
But Mr Justice Sweeney dismissed his plea, telling Wallis his "devious" actions "fell far below the standards expected of a police officer".
Mr Sweeney said his actions not only had an impact on Mr Mitchell but also had "a significant impact on public trust and confidence in the integrity of police officers".
In a victim impact statement Mr Mitchell described his devastation at Wallis's false accusations which "gave traction" to the story in Downing Street.
He wrote: "The existence of the emails contributed to my acute demoralisation and sense of isolation. They were therefore a contributory factor in the events which led to my resignation."
Following reports of the incident in 2012, the Sutton Coldfield MP apologised for being disrespectful to police but denied Pc Rowland's claim that he used the word ''pleb''.
Political pressure on Mr Mitchell intensified and eventually led to his resignation on October 19, a month after the initial altercation.
Two emails from Wallis to Mr Randall during that time were read out by prosecutor Zoe Martin.
In the email of September 20, he says: "I write to complain at the absolutely digesting (sic) behaviour displayed by your fellow member of parliament."
Sometimes writing in capital letters and misspelling words, he claimed he and his nephew witnessed Mr Mitchell's "unacceptable behaviour" but he "did not expect anything to come of it".
Mr Randall did take up the complaint. An investigation got under way at Westminster and a story ran in The Sun the following day.
As the situation intensified, a Channel 4 news team went to Wallis's home and confronted him about the email but Wallis denied knowledge of it.
Shortly before his arrest in December, Wallis seemed upset at work and his sergeant suggested he take time off, the court heard.
Wallis told a member of the Police Federation about contacting his MP because he was "disgusted by the incident", saying he had not mentioned he was a police officer.
Police investigating the incident eventually found out Wallis was a constable and he was arrested for misconduct in a public office.
In an interview, Wallis told officers: "I knew I should have thrown myself under a train yesterday."
Initially Wallis stuck to his story but when confronted by the CCTV evidence, he came clean, the court heard.
He told police: "I thought in a stupid, naive pathetic way I was backing up my colleagues. I just convinced myself I was there."
He went on to apologise for letting down the Metropolitan Police, his family and Mr Mitchell.
Ms Martin said Wallis was "mortified by the disgrace" of his actions.
Mr Gibbs told the court that events "got completely out of hand" and Wallis, who had been deeply affected by the death of his father, never wanted Mr Mitchell to lose his job.
After the sentencing, Met commissioner Sir Bernard Hogan-Howe said Wallis would be the subject of a misconduct process "as soon as possible".
He said: "I expect my officers to serve the public without fear or favour. Where officers break the law, they must expect to be held to account and answer for what they have done.
"Yesterday I apologised personally to Mr Mitchell that an MPS officer clearly lied about seeing him behaving in a certain manner. Today, I apologise to the public for Pc Wallis's behaviour."
Two officers from the diplomatic protection group (DPG) have received final written warnings and a third officer has undergone management action in relation to inappropriate comments, the Metropolitan Police confirmed.
Wallis, along with four other officers from DPG, will be the subject of gross misconduct hearings due to start at the end of the month.
John Tully, chairman of the Metropolitan Police Federation, said: "It is hugely regrettable that Pc Wallis decided to take the course of action he did in respect of his having witnessed the Downing Street incident (Plebgate).
"His actions have undermined public confidence in the police service in general and have muddied the waters in respect of the original incident. He has admitted his guilt in the criminal proceedings and must face the consequences.
"It must be emphasised that the great majority of police officers display courage and dedication in their daily duties and work tirelessly and honestly to keep their communities safe."