David Mellor has said he is "really, really sorry" after being recorded launching an expletive-ridden tirade at a London cab driver last week.
The millionaire former Cabinet Minister was branded "pompous' after being caught on tape ranting at a taxi driver, calling him a "smart-arsed little git" and a "sweaty, stupid little shit."
Mellor said he had a case for his annoyance, but threw it away with his foul language.
He issued the apology for his foul-mouthed rant during his first phone-in session on his LBC radio show since the incident. He said he "can't" and "won't" defend his actions.
Mellor began the show by telling listeners he was "really, really sorry" and promised to make a "substantial donation" to the Licensed Taxi Drivers Association's Christmas charity appeal.
He said: "I can't think what possessed me to lose it with that cabbie the way I did.
David Mellor leaves Global Radio in Leicester Square on Saturday
"OK, I had a case but I threw it away by the way I spoke and I'm really, really sorry about that, and I especially want to apologise to you, our listeners, for trying your patience and risking my own credibility with you by speaking the way I did.
"Anyway, it's water for me at the next celebratory lunch, I've definitely made that decision."
Mellor, a QC and former Conservative MP, was caught on tape telling the cab driver how vastly superior he was to him during a fierce argument about the route he wanted to travel last Friday.
The ex-Tory, who had accompanied his partner, VisitEngland chairman Viscountess Penelope Cobham, to an Investiture ceremony with the Prince of Wales, was heard in a mobile phone recording given to The Sun.
David Mellor with his partner Penelope Cobham at Buckingham Palace when Cobham collected her CBE
The paper reported that Mellor, who served as national heritage secretary in Sir John Major's government, accused the driver of not taking the quickest route to their destination in east London during rush hour.
During the audio, Mellor, who told the driver to "fuck off", threatened to name him and discuss the incident on his LBC radio show, which he co-presents with former London Mayor Ken Livingstone on Saturday mornings.
"I don't want to hear from you, shut the fuck up," he said.
"You've been driving a cab for 10 years, I've been in the Cabinet, I'm an award-winning broadcaster, I'm a Queen's Counsel. You think that your experiences are anything compared to mine?"
"Just shut up," he added. "Drive me whichever way you want, and keep a civil tongue in your head."
Despite Mellor's boasts of grand accomplishments, others reacted to the explosive recording with less than admiration at the time the recording was revealed.
Mellor also accused the taxi driver of "ruining his wife's day".
"See what you've done to her," he said. "She's telling me I've ruined her day. YOU fucking ruined her day. She's been at Buckingham Palace, she's seen Prince Charles, received a major award, and you, smart-arsed little git, have ruined her day. Are you proud of yourself?"
Mick Cash, the general secretary of transport workers' union the RMT, said the "appalling incident" will fuel a respect campaign.
Cash initially reacted to the news by calling Mellor "pompous."
Today he said Mellor's apology is "better late than never."
"Of course he has shone a light on both the attitude of the elite to the working classes and the sort of abuse taxi drivers and other transport workers are subjected to day in and day out," he said.
"This appalling incident will fuel RMT's respect campaign for all transport staff out there on the front line."
The former politician said on his show that he was in fact "one of London taxis' best customers".
He told listeners that Steve McNamara, general secretary of the Licensed Taxi Drivers Association, had said "I've picked him up myself. He's actually a very nice guy. Despite everything he said, he's not a bad guy."
The London taxi branch of the Rail, Maritime and Transport union said last week it was to consider a formal boycott of the former Tory minister.
GMB professional drivers branch president Simon Rush called for a public apology from Mellor, adding: "Whatever the reason for this loutish verbal attack on a working person by this politician, it is unacceptable behaviour, not only on the road but in any workplace. This is not the first time we have seen arrogance and conceit from Mr Mellor. A public apology from Mr Mellor is in order.
"It doesn't seem to matter how long you have been a fully qualified and experienced taxi or private hire driver, some of your passengers think they know better than you do.
"People are using their mobiles to tell you which route to follow and sadly this often leads to abuse of the driver. The implication is that you are dishonest when in fact you will be taking the quickest route based on your accumulated knowledge of all the factors such as time of day, traffic flow, road works etc, none of which the maps software will take in to account."
Mellor has previously been branded "repellant" for calling a child abuse victim "a weirdo."
He resigned in 1992, blaming his departure on a constant barrage of hostile stories in the tabloid press.
His resignation followed the revelation that Mona Bauwens, the daughter of a senior member of the Palestine National Fund, had paid towards his holiday.