Other countries’ corruption scandals are usually intrinsically dull. I know, for example, that there is a scandal in Washington involving a corrupt lobbyist and various members of Congress, but I cannot summon up enough interest to follow it closely. Likewise, the fraud case that has engulfed Ariel Sharon’s son is doubtless fascinating for Israelis, but the details send me to sleep. Most countries have at least one corruption story running at any one time, and Italy probably wins the Oscar for quality as well as quantity.

So it was that the progress of a long-running investigation by a Milan prosecutor into Silvio Berlusconi’s tax affairs did not exactly mesmerize the British press, even though the Italian Prime Minister faces a general election on April 9. Tax evasion, after all, is as Italian as spaghetti.

Until, that is, the prosecutor revealed last month that the investigation had involved a British tax lawyer called David Mills, who happens to be the husband of Tessa Jowell, the culture secretary and a Cabinet minister. It seems that Mr. Mills had received a $600,000 “bribe” from agents of Mr. Berlusconi, and that his wife had signed a mortgage application that enabled him to access this money from an offshore tax haven. Ms. Jowell, who protests her innocence, has rarely been off the front pages ever since.

Last weekend, it was announced that she was separating from her husband, who had apparently misled her about what he was up to. Mr. Mills had left the country; nobody knew where. Ms. Jowell was pictured, looking less than her usual soignee best, taking refuge at the country house of her friend and Cabinet colleague Charlie Falconer, the lord chancellor. The word went out from Downing Street that, provided no new evidence came out, she was safe.

On Monday, Ms. Jowell came to the House of Commons to be greeted by a wave of sympathy from Labor ranks. One comrade even compared her ordeal to a “McCarthyite witch-hunt,” though it is hard to see why Ms. Jowell, who has at the very least broken the ministerial code of conduct and may have been party to serious fraud, ought not to be called to account.

What, though, about the husband, now a mere embarrassment? Cherchez le mari! Yesterday, it was reported that Mr. Mills is in the United States, there to await a decision by the prosecutor in Milan, possibly today, about whether he is to be indicted on charges of accepting a bribe. This ball may eventually land in an American court.

Not surprisingly, Mr. Berlusconi has been at pains to distance himself from Mr. Mills, who is alleged by the prosecutor to have set up offshore tax shelters for the Italian Prime Minister. “I have sworn on my children’s life that I didn’t know anything about the money belonging to Mr. Mills,” declared Mr. Berlusconi, who now claims to have no memory of meeting him. That just about sums up the difference between the two political cultures: a British politician survives by dumping her husband, an Italian by swearing an oath on his bambini.

It turns out, however, that the authorities in both countries have been investigating Mr. Mills for quite some time. In a letter to the London Times, Charles Clarke, the home secretary, yesterday set out the sequence of events whereby the Italians began proceedings to extradite Mr. Mills two years ago, and warrants to search his property were issued by Scotland Yard. Mr. Clarke’s purpose was self-serving – to prove that he had not interfered at any stage – but the effect is to underline the proximity of his Cabinet colleague to a criminal investigation.

Meanwhile, the parliamentary commissioner for standards, Sir Philip Mawer, interviewed Ms. Jowell this week about whether she had accurately declared her interests as a member of Parliament. It appears that Mr. Mills also disguised his profit from share dealings, but Ms. Jowell was able to satisfy Sir Philip in half an hour that she had not knowingly made a false declaration.

This is very odd. In 2003, Sir Philip Mawer spent more than six months investigating comparatively trivial accusation against the then leader of the Conservative Party, Iain Duncan-Smith, that he had paid his wife, Betsy, who was also his part-time secretary, more of his office allowance than her services warranted. That investigation cost Mr. Duncan-Smith – the most pro-American Tory leader since Mrs. Thatcher – his job, even though he and his wife were entirely exonerated. Mrs. Duncan-Smith, a transparently honest woman, still has nightmares about the many hours of futile cross-examination she was subjected to by Sir Philip. Now that really was a witch-hunt.

So why should New Yorkers care about Tessa Jowell? Who, or why, or which, or what, is the secretary of state for culture, media and sport?

Her real job, to judge from her public appearances, is as minister for the London Olympics – remind me, someone, to immigrate to New York in 2012 – in which capacity she is chiefly responsible for preventing the astronomical sums of public money being spent on the games from being siphoned off by corrupt contractors. She has also introduced a new gambling law designed to put a casino in every town, awards licenses to broadcasters and the National Lottery, and presides over many other financial transactions in fields notorious for corruption. The holder of this office must be above suspicion.

But Ms. Jowell has another function, too, which has been much in evidence over the past few days. She is one of Tony Blair’s most loyal lieutenants.

On Monday evening, fresh from her triumph in the Commons, Ms. Jowell attended a performance of “Othello.” No doubt the culture secretary has a professional interest in Shakespeare, but this particular version was a school play directed by the Blairs’ teenage daughter Kathryn. Afterward, she was hugged for the cameras by the prime minister’s wife, Cherie.

To be a knight or dame of King Tony’s roundtable entails an ethos of sacrifice. One minister was given 10 minutes to choose between his wife and his mistress. Both Ms. Jowell and Mr. Mills had left previous spouses and children for the sake of their very political marriage. Both knew the rules. And Tessa passed the test. Having cut her husband loose, she was immediately welcomed back into the fellowship of the Ring. Greater love hath no woman than this, who would lay down her marriage for her political friends.