Why do politicians never resign for the right reasons?

I FEEL a particular sympathy for Joe Ashton, the Labour MP who has decided not to stand for the next Parliament after being caught in a massage parlour. For I too have ended up in what is inevitably called a Seedy Sauna offering kinky services, and you may or may not choose to believe the explanation.

When people are stationed in Moscow, the traditional steam bath and massage are standard treats for the pallid community of foreigners throughout the long winter months. When a Russian contact heard that my fiance was arriving for the weekend, he offered us the gift of a day in a sauna frequented by the cream of the Russian government. Ooh, we thought, that will be nice: a back rub, a circulation-enhancing beating with birch twigs and the mere possibility of the Interior Minister being in the very next cubicle.

It did not go like that. We should have been warned by the orgasmic pop music and the Polish pornographic posters featuring maidens with their swimming costumes on backwards. Anatoly, the masseur, was puzzled by our insistence on keeping towels with us and kept asking piteously whether we needed anything else, or should he bring in another woman or a friend? Eventually, my fiance uttered the heroic British understatement: "Er, something's not right here", and we made our excuses and left, followed by hard stares and mutterings about time-wasters.

Mr Ashton does not appear to have been so naive. But there was nothing illegal in his attending the parlour; he did not pay for sex and nor was the option put to him. The poor man hadn't even got into his bubble bath when the police arrived. He had no need to offer Tony Blair his resignation.

It may raise a snigger to learn that the sort of ageing Labour MP whose earthly pleasures we imagine to be two pints of bitter and a packet of pork scratchings turns out to relish body-to-body friction with a sprightly Thai, but so what? Sexy massages are not outside the law. If anyone got over-excited it would appear to be the police, who battered down the doors with sledgehammers to find out what value Mr Ashton was getting for his money.

Peculiarity is not the same as transgression. Most of us, at some time, do things which would look very odd to other people. To their credit, Labour officials have decided not to get steamed up about Mr Ashton's sauna, although they might not have been so tolerant had he not offered to stand down after the next election anyway.

On more serious resigning matters though, they seem to be in some confusion. Mohammed Sarwar was suspended on suspicion of buying votes in Glasgow, while Fiona Jones in Newark was backed by the party. This turned out to be exactly the wrong way round: Mrs Jones has been found guilty in court of over-spending in her election campaign in Newark and unfit for office, while Mr Sarwar, who was hung out to dry by the party managers, was last week cleared of wrongdoing.

When exactly MPs should resign is an inexact science in which their general standing matters more than what they have done. In November 1947 Hugh Dalton stood down as chancellor because of a budget leak to the London Evening Star. But the same year, another senior cabinet minister, AV Alexander, had committed a major indiscretion by letting slip that the chancellor would make a speech on suspending the pound's convertibility. Alexander survived; Dalton, by this stage dispensable to a government seeking a fresh start, did not.

The exact grounds for Peter Mandelson's resignation were unclear - was it taking Geoffrey Robinson's home loan? Or negligence in declaring it when Mr Mandelson became trade minister and the DTI was looking into Mr Robinson's affairs? Or the failure to declare the loan on his mortgage form? The real answer is: none of the above. Mr Mandelson resigned because he was shrewd enough about modern politics to know that the appearance of what he had done discredited the Government and that he would have a better chance of reviving a senior political career some day if he fell on his sword at Christmas.

In their evasions, double-dealings and infidelities, politicians are like the rest of us, only more so. It is unreasonable to expect them to uphold different standards to those which apply in the rest of society, and the public is far more tolerant of foibles than the press or the prurient political establishment. Kenneth Starr learnt this the hard way when the nation failed to recoil in horror over Bill Clinton's fumblings with Monica, but recoiled in horror at Mr Starr.

John Major made the cardinal mistake of expecting his Tories to be better behaved than the population at large. Mr Blair, watching the comedy of errors of David Mellor, Tim Yeo and finally, with impeccable pre-election timing, Piers Merchant, determined that when he was in charge, sex wouldn't count as grounds for going. Robin Cook was a beneficiary. But Ron Davies's adventures on Clapham Common showed how one deception so often entails another, so that by the end it was difficult to tell whether it was Davies's lying or his alleged soliciting that was deemed to be the resigning matter.

If there is a risk in Blairite sexual liberalism, it is that it inclines to make judgments based on palatability rather than consistency. Heterosexual adultery is an abyss into which many happily married people gaze now and then, whether or not they leap. It is easy to tolerate failures in others with which we empathise; far easier to cast the first stone at someone whose foibles seem weird to the mainstream.

A day after Mr Ashton's headlines it was revealed that Pauline Green, the leader of the socialist group in the European Parliament, often has her Brussels chauffeur drive from Brussels to London, while she flies, and boards him in hotels so that she can be driven around in Britain by him when on business. This is the sort of minor lunacy that seems normal to people who have had their standards warped by exposure to so much extravagance that they no longer notice their own.

Naturally, it did not strike her as an excessive perk. What would? Justifying the unjustifiable is an art in which she has some practice. She refused to back a no-confidence motion in the Commission when the scale of fraud and croneyism in Brussels was exposed, only to join the calls for its resignation when it was clear that Jacques Santer and his clique were doomed.

The trouble with resignations is that they so rarely happen for the right reasons.