Leading article: A harbinger of the bitter strife that may lie ahead

John Prescott's croquet game at his tax-payer funded country residence risks costing him dear. The pictures of him engaged in this gentlemanly summer pursuit distilled so many of the contradictions in his current position. The well-remunerated Deputy Prime Minister with not a lot to do. The supposedly working-class lad disporting himself on his country estate. The rather juicy perks he retains, despite the loss of his departmental responsibilities. What a gift; what an open goal.

His critics, though, protest too much. Playing croquet on a Thursday afternoon is not a capital crime. If anything, it is a misjudgement, and one that is more the stuff of comedy than tragedy. Mr Prescott's relationship with a member of his staff, conducted at least in part in work time and on office premises, was an infinitely more serious indiscretion. If the Prime Minister decided to not to remove him in the latest reshuffle, despite his affair with Tracey Temple, it is difficult to argue that he should be dismissed over his "away-day", so called, at Dorneywood.

It is also petty in the extreme to argue that Mr Prescott should be punished by losing the use of Dorneywood and his grace-and-favour flat at Admiralty House. If these are perks that Mr Prescott was accorded as Deputy Prime Minister, let him keep them so long as he keeps that job. We may not like the fact that the Prime Minister has so many valuable perks in his gift. And we might think it unseemly that the beneficiaries of these privileges often cling to them so grimly. Once granted, though, perks cannot be treated as points that can be withdrawn one by one for bad behaviour.

No, what is significant about the croquet game is not the fact that it happened, nor yet that it was photographed, but that these still, slightly fuzzy images so quickly revived the controversy surrounding Mr Prescott. Whereas few MPs had commented when the Tracey Temple affair hit the headlines before the local elections, this time several MPs and other Labour luminaries took less than 24 hours to take sides.

The Secretary for International Development, Hilary Benn, came out in Mr Prescott's support, as did the Mayor of London, Ken Livingstone. A number of Labour backbenchers, however, said the Prime Minister should remove Mr Prescott as Deputy Prime Minister. One said the party needed to mend fences with women voters who were furious that Mr Prescott had got off so lightly over his affair. Most lethal was Peter Mandelson, who told the BBC he expected the Deputy Prime Minister to act in the party's interests rather than his own.

This swift taking of sides suggests that far more is at stake than Mr Prescott's continued access to a croquet lawn. In the quarrels over the Deputy Prime Minister's fate we are seeing the clearest signs yet of end-of-regime instability in the parliamentary Labour Party. This is no more nor less than a proxy war, early skirmishing for the succession to Tony Blair. If not effectively handled, it could be a precursor of nastier things to come.

Unless Mr Prescott takes Mr Mandelson's advice, Mr Blair will have hard decisions to take on his return from holiday. He will have to calculate whether the ridicule to which Mr Prescott is widely subject makes him more of a liability to the Government than an asset. Were he to replace him, Mr Blair would have to decide what signals that might send about the succession. He would also have to judge whether an angry Mr Prescott might not resign as deputy chairman of the party, precipitating an unwelcome election for the post. None of this is simple. The awkward truth is that Mr Prescott's troubles are not just about Mr Prescott, they are also about the succession to Tony Blair. As such, they presage dangerous times, for the Government and for the party.