When political misfortunes accumulate it is natural to ask whether seemingly separate and random events have a common cause. British Prime Minister Tony Blair's leadership of his government and party has come under intense scrutiny after a dreadful Wednesday in which the home secretary apologised for gross incompetence over prisoner releases, the health secretary was booed and heckled at a nurses' conference and the deputy prime minister admitted having an affair with his secretary. Can Mr Blair turn these fortunes around or is he a liability for Labour's hold on office? This is the key question which will determine his continuing leadership.
There are other challenges to come. Next week's local elections are expected to go badly for Labour and so is a forthcoming parliamentary byelection. Mr Blair has still to explain satisfactorily why rich businessmen who gave secret donations to Labour were offered peerages. His education bill introducing market choice for schools has got through the Commons only with Conservative support. The principles on which it is based are similar to the health reforms he has championed and are unpopular with his party's left-wing. Above all, this crisis will increase party factionalism about when he should retire as leader to make way for Gordon Brown.
There is no indication that he is ready to do so. He still sees this agenda as incomplete, requiring at least another year's effort. To secure his legacy he needs to deliver on these reforms, distance himself from Iraq and if possible see power-sharing restored in Northern Ireland. Sentiment has not so far decisively changed within the parliamentary Labour Party to force the issue. But these are highly precarious days, since all three of the ministers directly exposed are close political allies. Should one of them have to resign, attitudes could rapidly change - and next week could be just as difficult.
Comparisons with the Conservative Party's famous Black Wednesday in 1992 when sterling was forced to withdraw from the European monetary system, or with the sleaze accompanying the latter years of the Major government, are inevitable but misleading. The British economy remains strong and earnings are comparatively buoyant. The Conservative opposition has only a marginal lead in the polls and has not convinced the public it could run the country better under its new leader David Cameron. Protest votes are likely to go to the Liberal Democrats or far right rather than to the Tories. Mr Blair is known as a resilient leader and will probably be given another chance.
But this week underlines that his period is drawing to a close. This is not just an impression from the frantic media coverage - which Mr Blair disparages but is obsessed by. His government needs renewal and redirection if it is to weather these difficulties. The more serious they become the more this will be seen as a job for a new prime minister rather than another example of how capable Mr Blair is of weathering a storm.