We sometimes wonder if dear old Boris Johnson is suffering from that incurable condition known as foot in mouth disease.

The Henley MP is notorious for occasionally opening his mouth before engaging his phenomenal brain.

That is why he is not exactly welcome in places like Portsmouth and Liverpool after well-chronicled attacks on those cities.

So nobody should be surprised that Boris is at it again, with his astonishingly frank admission that he took cocaine and smoked more than a few spliffs in his younger days before entering politics.

Doubtless Tory leader David Cameron will be less than amused at Boris's latest pronouncement, having steadfastly refused to discuss his own rumoured drug dalliances as a young student at Oxford University.

Indeed, Mr Cameron's stonewalling stance is the common one among politicians from all major parties.

But Boris Johnson is not just any old politician. By breaking ranks in this way, he is sure to face stinging criticism from all sides.

The fact is that all this happened a long time ago and in the same interview, with GQ magazine, he stated quite clearly that he is now a committed anti-drugs campaigner.

As the vast majority of his fellow MPs would run a mile rather than give a straight answer, we'd suggest Boris is guilty of only one thing - being honest.