So which affair will cost Labour the most votes?

The Charles Clarke affair

The fiasco over the release of foreign prisoners is a nightmare for Labour activists. The timing of the disclosures - nine days before polling - was bad enough. But more damaging details have been dragged out of Charles Clarke since.

One canvasser in London said: "The Home Office stuff is really bad news - people have been put in danger - and it is doing deep damage."

Labour has spent years trying to build a strong image on law and order. Strategists fear much of that work could have been undone in just days.

The episode also touches on immigration - a toxic issue for the party particularly in areas where it faces a challenge from the British National Party.

Above all, it gives an impression of managerial incompetence at senior levels of the Government.

Liability rating: 5/5

The Patricia Hewitt affair

The spectacle of a Health Secretary being heckled by nurses the week before local elections could have spelt disaster for Labour. But the incident has been obliterated by the appalling publicity generated by Clarles Clarke and John Prescott. Labour foot-soldiers insist the subject is barely mentioned by voters, who tend to ask detailed questions about local hospitals rather than debate NHSreform at national level. Where hospitals are threatening to lay off staff, the doorstep exchanges have been trickier. However, the party believes the issue is a strong suit for Labour, because of public misgivings over the Tories' intentions for the NHS. A London canvasser reported that most voters did not even know Ms Hewitt's name, which he took as a good sign.

Liability rating: 2/5

The John Prescott affair

Labour activists are discovering a mixture of amusement and anger on the doorstep over the Deputy Prime Minister's amorous antics. They insist no one is going to change their vote as a result of Mr Prescott's philandering - the public already feel strongly one way or another about him. A canvasser in the east Midlands said: "Men in particular seem to think it's a bit of a laugh."

One activist even said he hoped the saga ran to polling day, to distract from the more hazardous topic of foreign criminals. However, the Ealing MP Stephen Pound said: "There is a real problem there, and on the doorstep I have to say that it is one that is causing huge problems."

Party chiefs also know the subject eats into Labour support in an insidious way, adding to a feeling of an administration in its decadent final phase.

Liability rating: 3/5