David Mellor has been exposed as an awful man, but should he have been?

Nevertheless, we shouldn't allow our prejudice, and our desire to think the worst of a man who seems hopelessly in love with himself, to infect our assessment of a set of circumstances that saw Mr Mellor on the tabloid front pages for the first time for more than 20 years.

Mr Mellor was secretly recorded by a London cabbie the other day, and the tape certainly doesn't make one warm to the former Cabinet minister. He uses foul language, employs the most odious de haut en bas conversational style imaginable, and, as if that's not enough, he does a fair bit of the old do-you-know-who-I-am routine. It's safe to say that the taxi driver knew exactly who he had in the back of his cab, which is why he activated - without Mr Mellor's knowledge - his recording device, which subsequently was sent to The Sun.

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I'm not sure whether what the cabbie did was legal. Perhaps we need a Queen's Counsel to tell us. Luckily, as he imperiously informed the driver several times, Mr Mellor is one, but he - now cowed by the predictable moral outrage - can't challenge the legality, or even morality, of recording a private conversation without permission and then seeking to publish it for financial gain. All Mr Mellor can do is apologise for his intemperate behaviour, keep his head down until the storm blows over, and get an account with Uber (a reliable service, and normally cheaper than black cabs, anyway).

How many of us would survive having our daily conversations, or more particularly our disputes with colleagues, or even (in my case) the odd contretemps with a cab driver about the best way from A to B, broadcast to the wider public? We have a right to expect private conversations, or one-on-one exchanges with strangers, to remain private. That is not to excuse or condone Mr Mellor, but it's worth bearing in mind.

There is also something which does not quite add up here. When the tape starts, Mr Mellor is already quite exercised, and we don't know what his got his considerable dander up. When the record button is pressed, the cabbie - who pseudonomously refers to himself as Brian - is the very model of restraint, equanimity and conciliation. “If you've had a bad experience, I'll apologise,” he says at one point, but he's in a privileged position: he knows he's being taped, and Mr Mellor doesn't. We don't need a QC to say this must be inadmissable evidence.

And what was at the heart of the argument? Mr Mellor thought that the taxi driver was taking the wrong route from Marylebone High Street to near Tower Bridge. A journey of only 4.8 miles ended up costing a whopping £29 (without tip). I think David Mellor may have had a point.