Complete candour will clear the air

Cherie Blair's statement was a first. She and husband will be fervently hoping that it will also be a last. Never before has a Prime Minister's spouse been enveloped in such a swamp that they have been compelled to account for themselves on live television. Norma Major, Denis Thatcher, Audrey Callaghan, Vi Attlee, none of them, nor any other prime ministerial consort, has ever put themselves in such a horrendous place.

By her own account, Mrs Blair, a woman always highly suspicious of the press and now deeply wounded by it, broke her 10-day silence with huge reluctance. She did so only because the damage to her own reputation and that of her husband was becoming so severe. Just 24 hours before his wife's dramatic appearance, Tony Blair was still trying to pass it all off as a fleeting "media frenzy". Mrs Blair herself confessed to an urge to "crawl away and hide". Even before she uttered a word of it, her statement was a confession of how badly the Blairs have handled this episode.

Those attuned to the ways of New Labour will recognise that it conformed to the rules of crisis management laid down by Alastair Campbell. The only way to try to put a line under this corrosive affair, the only resort left available which might douse the intense media heat, was for Cherie to answer her acccusers in public. There were echoes in this of her husband's first encounter with sleaze five years ago when he was forced into a live television interview to apologise for the Ecclestone Affair. When all else fails, say sorry.

That Mrs Blair did, taking upon herself the blame for allowing Number 10 civil servants to issue misleading statements, and confessing that she had been foolish to become the mark for a convicted fraudster.

Did it work? As a piece of extraordinary theatre, I'd say that Mrs Blair will have helped herself in the eyes of many of the public. The Tories also clearly think so. Fearing she may have swung public sympathy, Conservative frontbenchers are reluctant to attack her personally.

Over the past 10 days, Mrs Blair has been relentlessly pilloried as a persistent dissembler and a loopy dabbler in cranky pursuits. The only way to challenge that caricature was to throw herself on the mercy of public opinion and allow them to judge the judge.

The strategy behind the statement was laid bare by the Cabinet Minister, Tessa Jowell in an interview last night when the Culture Secretary expressed the wish that "millions of people who will be watching would understand and feel for her". Mrs Blair's insistence that her primary instinct was to protect her eldest child, coupled with her plaintive appeal that "I am not superwoman", will probably have won her understanding at an emotional level.

As a full answer to all the allegations levelled against her, the statement was not complete. It still leaves several key questions unanswered. It also raises a fascinating new one: why did she check the court list to find out which judge would be presiding over Peter Foster's deportation case? The bigger question the Blairs would be wise to ask themselves over the next few days is how they must change to prevent anything like this ever happening again. First, they must henceforth adopt honesty as the best policy. The truth, the whole truth and nothing but the truth must be told, however much they may loathe the interrogators and however awkward or humiliating the truth may be. Because the lesson of this episode is that concealment just makes the humiliation 10 times worse.

Second, the Blairs have to erect much clearer boundaries between their private affairs and their public roles. Even if her intentions were as well-meant as she asserts, it was breathtakingly foolish for the Prime Minister's wife to involve herself in any way with the deportation case against Mr Foster.

Third, the Prime Minister should today ask the Cabinet Secretary, in consultation with the relevant watchdogs of standards in public life, to urgently review the rules on Ministerial conduct, including - but going further than - the guidelines which govern the operation of blind trusts. It is self-evidently wrong, ridiculously so, that the Prime Minister is the final arbiter of whether he has abided with the rules. He cannot be the umpire in his own case - and nor can anyone who is in any way beholden to or dependent on the Prime Minister. The rules on ministerial conduct should be policed by an independent ombudsman or commission.

Finally, the Blairs need to conduct an urgent and searching personal review of how they run their lives. Some astonishingly reckless lapses of judgment by two supposedly very clever people have done great damage to their hugely useful reputation as a decent, Christian couple. Even if Mrs Blair's statement succeeds in its purpose of bringing the curtain down on this affair, memory of it will linger on in the minds of many of the public.

Alastair Campbell can draw some grim satisfaction that his previous, unheeded warnings about Carole Caplin have been so vividly vindicated. And yet neither he nor anyone else can apparently convince Mrs Blair, who made several warm remarks about her friend last night, of the hazards involved in such relationships.

It is a tribute to Cherie Blair's loyalty that she seems determined to stand by the friend who helped land her in such an awful mess. I am not sure what it says for her common sense. Mrs Blair reputedly pays her lifestyle Svengali £5,000 a month for fashion advice, fitness tips and exotic therapies. The Prime Minister's wife needs to ask herself whether you can have paid friends - especially when they pay you back by embroiling you with a convicted conman.

When there are poisons in the body, Ms Caplin is said to prescribe the nude scrubdown. A political variation of that was what Cherie Blair attempted last night. Only an absolute commitment to plain and open dealing can completely detoxify Downing Street.