David Mellor has said he is "really, really sorry" for his verbal abuse of a London cab driver last week.
The former cabinet minister showed remorse for his foul-mouthed rant during his first phone-in session on his LBC radio show since the incident.
His apology has been welcomed by trade unions, and he is also donating to the Licensed Taxi Drivers Association's Christmas charity appeal.
Mr Mellor began the show by saying: "I can't think what possessed me to lose it with that cabbie the way I did.
"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."
Mick Cash, the general secretary of transport workers' union the RMT, said the "appalling incident" will fuel a respect campaign.
Mr Cash said: "David 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.
"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."
Mr Mellor will be making a " substantial donation" to the Licensed Taxi Drivers Association's Christmas charity appeal.