It can be safely assumed that the person responsible for planning the penultimate week of Labour’s efforts for the 2006 council elections did not intend to include the following: the Health Secretary being ridiculed for insisting that the NHS has enjoyed its “best year ever” and then being booed by nurses; the Home Secretary under- cutting the party’s campaign over law and order and antisocial behaviour by presiding over the improper release of 1,023 foreign national prisoners; and the Deputy Prime Minister (also the minister who is in charge of local government) being obliged to admit to a long sexual liaison with his secretary.

It is possible that Tony Blair has had worse days as Prime Minister. It is not immediately evident when they might have been. It has left the collective impression of a government that is out of touch in the first case, astonishingly incompetent in the second and morally unhinged in the third. If this particularly dark cloud has any silver lining at all for the Prime Minister, it is that if Labour does suffer an utter disaster at the polls next Thursday, there will be many other members of the Cabinet with whom he can share the blame.

John Prescott’s conduct might seem the least of this saga but it is a serious matter. Extramarital activity is hardly novel in politics (or other walks of life) but this relationship between a prominent politician and a civil servant in his office was unprofessional as well as unethical in other respects. This is not a resignation issue, but it will hardly be Pauline Prescott alone who thinks far less of her husband as a man and as a public figure after learning of the full details of this story. The Deputy Prime Minister is becoming a liability to this administration. The ugly aroma of the arrogance of power is rapidly attaching itself to him.

Charles Clarke can be charged with arrogance of a different character. The facts that have emerged in the past 36 hours about the failure to refer foreign national prisoners for potential deportation are damning. The Home Office was warned about this scandal in 2003, if not earlier, yet no serious action was initiated until two years later. Even at that point, July 2005, when a solution was supposedly being implemented, a further 288 former inmates were “lost” between an incoherent Prison Service and an inept Immigration and Nationality Directorate — both of which surely must be overhauled, as must the ministerial structure.

The Home Secretary is no fool and is a better-than-average Cabinet minister. This is not, nevertheless, a defence on this occasion. Mr Clarke is the son of a former high-ranking civil servant. He must appreciate that in past times the doctrine of ministerial responsibility would have demanded that a politician in his place accepted not simply the blame but the personal burden of such a shambles. If he did sincerely offer his resignation, he was right to do so. As capable as he is, Mr Clarke is living on borrowed time — one more mistake and he must go.

Patricia Hewitt is in a separate category. To be jeered at what in effect is a union conference, even of nurses, is no crime. In most circumstances, it may rather be regarded as a virtue. If the restoration of financial order in the health service requires a comparatively modest reduction in employees, that is not necessarily a tragedy either. An element of presentational skill in these conditions is, though, essential. Whatever her virtues might be in other regards, Ms Hewitt, as she showed again yesterday, is scarcely a reincarnation of Cicero. She is not in the correct portfolio.

Mr Blair’s Black Wednesday might be dismissed as just the dubious judgement of Mr Clarke and Mr Prescott. A portion of the blame, however, rests at the Prime Minister’s own door. It was he who conducted (another) botched Cabinet reshuffle in the aftermath of the general election and he has dithered about changing his team for six months after the second departure of David Blunkett. But it is clear, as we asserted last month, that many of his colleagues are round pegs in square holes. Once the painful local election results have been returned, Mr Blair will have surely his last chance to re-organise the Cabinet. He cannot afford another mistake.