THE membrane around the Westminster bubble must be as thick as, well, a couple of its supposedly brightest denizens.

In their new book, The Age of Earthquakes: A Guide to the Extreme Present, Douglas Coupland and his fellow authors coin some new words for our age, such as "smupid", meaning both smart and stupid. They did not have Malcolm Rifkind and Jack Straw in mind but to most observers of our endlessly self-unaware Westminster village it seems the perfect description.

We tried to be relatively gentle with both MPs yesterday, and indeed MPs in general, accepting that their pay scales may be on the low side for the probity we rightly demand of them. But sometimes people will not be helped.

Whatever Sir Malcolm now does with what remains of his career, we assume it cannot be in public relations. Mind you, never say never.

We would like to be recording a parliamentary career worth lauding - first as an Edinburgh MP and Scottish Secretary, going on to become Transport Secretary, Defence Secretary and Foreign Secretary, one of only four Ministers to serve throughout the whole 18 years of Margaret Thatcher's premiership.

Then, eight years after rejection by Scottish voters, he returned as MP for Kensington and Chelsea in 2005 to instant grandee status and, breathtakingly in the light of this week's episode, convenership of the Commons' Standards and Privileges Committee. Sometimes the phrase "you couldn't make it up" does not suffice.

But then new heights, for an Opposition backbencher, were achieved with his re-election to the Kensington seat and appointment as chairman of Westminster's Intelligence and Security Committee. His increasingly hawkish stance on international affairs - demanding fresh intervention in the Middle East without UN sanction - saw him appointed chairman of the World Economic Forum's "Nuclear Security Council" and, just last month to a post at the Organisation for Security and Co-operation in Europe.

So with all this in his locker, what on earth possessed a supposedly smart lawyer to offer to sell himself for a few thousand pounds a day to people purporting to represent a Chinese company, ergo the Chinese Government? It cannot just be that he thought his £67,000 as an MP and extra £15,000 as committee chairman - none of this a salary, apparently - were not enough to live on.

Sir Malcolm was caught, on camera and on tape as he touted for business, saying: "You'd be surprised how much free time I have. I spend a lot of time reading, I spend a lot of time walking. Because I'm not a minister or full-time working for one person I can sort out my day."

When doorstepped about this yesterday it would be fair to say he did not go down the road of apology or self-chastisement. "Mind your own business," he snapped as he went into what would be his final meeting as ISC chairman. He simply refused to recognise that this was indeed our business. We pay his salary of more than £80,000. He is not, as he told his bogus Chinese suitors, self-employed.

Worse, he said: "As regards the allegations of Channel 4 and the Daily Telegraph I find them contemptible and will not comment further at this time."

We have sad news to impart to Sir Malcolm. Both admirers and fair-minded commentators will disagree. They will see his conduct as contemptible, not the news organisations who revealed it. Entrapment is always cried as foul by those who are trapped. But sometimes it is the way you walk into a trap which speaks to your judgment.

It is possible to admire Sir Malcolm Rifkind's record as a politician and statesman, even where one disagrees with him. It is possible to have some sympathy for a politician in the final days of his political career making an error of judgment.

It is impossible to have sympathy with the arrogance of a politician who lashes out at his accusers and refuses to see that it is he who is in the wrong.