The lawyer for Plebgate PC claimed Andrew Mitchell was a "Jekyll and Hyde" character who displayed a foul temper and used foul language when at his most angry.
Desmond Browne QC also said media attacks on his client, PC Toby Rowland, had a "devastating effect", ITV News Political Correspondent Carl Dinnen has tweeted:
Rowland lawyer; There is a history of Andrew Mitchell and allies attacking PC Rowland through the media. It has had a devastating effect.
The police officer in the Plebgate incident lacked the "wit, imagination or inclination" to make up the exchange with Andrew Mitchell, Mr Justice Mitting has said.
The judge's ruling rejected the allegation there was collusion by the officers on the Downing Street gate following the row with the then-chief whip.
Mr Justice Mitting said PC Rowland was "not the sort of man who would have had the wit, imagination or inclination to invent on the spur of the moment an account of what a senior politician had said to him in temper".
Andrew Mitchell looked "grim-faced" throughout the verdict as he learned he had lost his 'Plebgate' libel action, ITV News Political Correspondent Carl Dinnen has tweeted.
PC Rowland impassive throughout the #plebgate verdict. Andrew Mitchell, with his family and David Davis, grim-faced three rows further back.
PC Toby Rowland claimed statements made Mr Mitchell from December 2012 onwards falsely suggested he had fabricated his allegations.
Mr Mitchell had denied saying: "Best you learn your f****** place - you don't run this f****** government - you're f****** plebs."
He said he would never call a policeman a pleb "let alone a f****** pleb" - although he agreed he muttered audibly under his breath 'I thought you lot were supposed to f****** help us' - but not at the officer.
The 58-year-old MP for Sutton Coldfield resigned as whip a month after the altercation.
The judge at London's High Court has said he is "satisfied" Andrew Mitchell did use the "politically toxic word pleb" in the exchange with PC Toby Rowland at the Downing Street gates.
ITV News Political Correspondent Carl Dinnen relayed Mr Justice Mitting's words from court, tweeting:
#Plebgate Judge; I am satisfied heat Mr Mitchell did say the words alleged or at least something close to them....
#Plebgate Judge; Mitchell too angry to remember what he said. PC Rowland too unimaginative to make it up. Mitchell probably said 'Pleb'
Mr Mitchell sued News Group Newspapers (NGN) over a September 2012 story in The Sun that claimed the then-chief whip had a branded police officer a "f****** bleb" for not allowing him to cycle through the Downing Street gate.
NGN based its report, which it said was substantially true, on the account given in his log by PC Toby Rowland.
Former Government chief whip Andrew Mitchell has lost his High Court libel action over the "Plebgate" incident.
Mr Mitchell attempted to sue News Group Newspapers (NGN) over claims he called police officers "f*****g plebs" during an incident at Downing Street.
The PC at the heart of the 'Plebgate' row has told the High Court he did not know what the word 'pleb' meant at the time it was allegedly used by MP Andrew Mitchell.
Toby Rowland is suing Mitchell for libel over statements accusing the PC of fabricating the alleged verbal abuse.
Mitchell, meanwhile, is suing News Group Newspapers (NGN) for libel over their reporting of the incident.
A Sun newspaper story alleging Andrew Mitchell called police officers was a "disgraceful piece of journalism", the MP has told court.
However, the former government whip accepted that police had complained about his behaviour, as ITV News Political Correspondent Libby Wiener reports.
A number of well-known figures have offered statements in defence of Andrew Mitchell in a libel trial over the 'plebgate' row, with Lord Coe calling the former minister "a man of integrity".
"I have heard Andrew use fruity language in the past but I have never heard him use the word 'pleb'. My instinct is that he would not have done so in this instance," the former head of the London Olympic campaign said.
MP Kenneth Clarke also told court that Mitchell could be "a little hot tempered, but never in malice".
"I have never known him to be dishonest or untruthful in any way and I would be prepared to put a very great deal of confidence in anything that he told me."
Mitchell is suing News Group Newspapers (NGN) for libel over claims he called police officers "f*****g plebs" during an incident at Downing Street.
Bob Geldof told the High Court he was a "pleb" but Andrew Mitchell was not as he offered a defence of the MP in a court hearing over the 'Plebgate' row.
Geldof provided written evidence in support of his friend the former minister, who is suing News Group Newspapers, saying he had never been patronised by him.
"We are an unlikely pair of friends," he said. "I came from a poor Irish, not particularly well educated background and he does not."
I am in fact 'a pleb' and he is not. Never once in all our time did he patronise me, talk down to me, behave in a superior manner to me, deride, insult or dismiss me or my opinions.
He also called Mitchell - a friend since shortly after the 'Plebgate' row - "open, frank" and "truthful", adding: "But not once in all of this time did I EVER hear him use the ridiculous and archaic expression 'pleb'!"
A lawyer representing Toby Rowland - the PC at the heart of the 'Plebgate' row - has alleged that MP Andrew Mitchell was "desperate" to see the policeman prosecuted.
As ITV News Political Correspondent Libby Wiener reports, Mitchell told court he was only desperate for justice.