Portillo 'misspeaks' on Mitchell's use of the word 'pleb'
Michael Portillo has said he "misspoke" when he claimed he had heard former Conservative chief whip Andrew Mitchell say the word "pleb".
Mr Mitchell resigned his post in 2012 after Downing Street police accused him of calling them plebs during a row - a word he denied having used.
In a live discussion on the BBC's This Week, Mr Portillo revealed: "I have heard him use that word in private conversation - the pleb word, I mean."
But he now says he got "carried away".
Pressed on the This Week programme on Thursday about whether he had heard Mr Mitchell use the word, Mr Portillo said: "I think I did, but not in a bad context.
"Some policeman thought: 'Ah, that's a word that people will believe that Andrew Mitchell might have used.'
"But he wouldn't have used it in that context."
On Friday, the former Conservative cabinet minister added: "I seem to have misspoken. I had no right to say that.
"I think I got carried away in the heat of the moment. I did not mean to say it and I want to withdraw it."
The former politician, who served as defence secretary under John Major, is a regular pundit on the show.
Mr Mitchell admitted swearing during the September 2012 row with police officers who said he could not ride his bicycle through the main Downing Street gate.
But he also maintained: "I think most people who know me know I would not use words like pleb or moron in describing anyone."
The Conservative MP has claimed that the officers involved conspired against him in a bid to "toxify" his party.
After a meeting with Mr Mitchell at his Sutton Coldfield constituency office in October 2012, three local representatives of the Police Federation criticised the MP for casting doubt on the Downing Street officers' version of events, said he had refused to disclose the exact words he had used in the row, and had "no option but to resign".
Mr Mitchell has an audio recording of the meeting, which shows he did admit swearing during the original incident but denied using the word "pleb" or insulting the police.
The chiefs of West Mercia, West Midlands and Warwickshire police forces concluded that no disciplinary action was needed against their officers, even though an internal investigation by West Mercia Police had initially said there was a "case to answer for misconduct".
The Independent Police Complaints Commission (IPCC) has said the officers who spoke to Mr Mitchell should have faced misconduct hearings, and Prime Minister David Cameron has said the MP is "owed an apology".
Eight people have been arrested and bailed under Scotland Yard's investigation into the affair, including five police officers.
The Crown Prosecution Service is considering whether to bring criminal charges against any of them.