Mark Seddon: Only the election will put an end to this feud

Until now, Brown and Blair have always known that they hang together or are hung separately

Why does Endemol Productions go to so much effort to find contestants for its execrable Celebrity Big Brother, when the show is coming free from that other house of varieties, the House of Commons?

Why does Endemol Productions go to so much effort to find contestants for its execrable Celebrity Big Brother, when the show is coming free from that other house of varieties, the House of Commons?

The longest-running end-of-the-pier show in politics - the Gordon versus Tony pantomine - is in danger of proving former Mirror editor Piers Morgan right. "Politics", he once said "is showbiz for ugly people". It is, however, showbiz that the poor bloody infantry in the Parliamentary Labour Party could do without - as some of them made clear to a clearly chastened Prime Minister and Chancellor during their meeting on Monday night. Should the estimable Clive Soley, a former Chairman of the PLP, follow through with his threat of naming the Brownite whisperers behind Robert Peston's explosive book, Brown's Britain, the last few days may prove only the warm-up.

The protagonists have agreed to cool it. Perhaps it was a hilarious intervention from the Labour backbencher Diane Abbott on television demanding "unity" that brought them down to earth. Whether Tony and Gordon can remain on speaking terms for another three months may depend on the publication date of a threatened book from Andrew Rawnsley - as close to the Blairists as as Peston is to the Brownites. So far, just, Tony Blair still holds the upper hand. He didn't say - as Harold Wilson once exhorted to Hugh Scanlon - "Get your tanks off my lawn!", but Gordon's tanks are nonetheless withdrawing once again.

This battle of the books, a battle that also extends to the Westminster beltway of journalists and commentators, is one of proxy. It leaves most MPs as spectators, never mind the vastly diminished band of Labour activists.

It would be easy to claim that the row that has shaken New Labour to its foundations revolves around frustrated ambitions and bruised egos. That may be part of the story - and there is no doubt that Brown's ambitions have been thwarted. He believes that he could be doing a better job than Blair. This is a conviction with which most voters and Labour supporters now appear to agree.

Yet the battle of the books is also a tale of repressed passions and convictions, a story of two powerful chieftains, one a brilliant communicator who travels light and the other a political heavyweight, of Denis Healey proportions, but without the impish sense of humour. Both Blair and Brown were equal architects in the building of New Labour but, tellingly, Brown believes that Blair "misunderstood the real meaning of the 1997 general election landslide". This is not code; it marks the public opening of an ideological divide over the whole future of the Labour Party.

The frustrations also spill from the joint project that bound the two men so close - a distaste for pluralism and dissent that, in turn, led to a great political movement being turned over to a system of "command and control". The battle of the books is a substitute for proper cabinet-style government where contentious policies are thrashed out, a substitute for a party conference where members can help make policy, and a substitute for Parliament itself.

Instead, private grievances are trotted out to favoured authors. The mask is however restored when anyone else steps out of line. "Command and control" is another description for "democratic centralism", a phrase familiar to many an ex-Communist and Trotskyite now in government. It is at the root of the decline of Parliament, cabinet and party.

Until this moment, Brown and Blair have always known that they hang together or are hung separately. I suspect that this fraught double-act will continue until the general election. But what happens beyond that largely depends on New Labour's majority, whether it is large, small or Parliament is hung.

If small, the endgame for the Blair era - and New Labour is in sight. It would be difficult in any event to see what enjoyment Tony Blair might gain from having to negotiate each passage of his "unremittingly New Labour" programme with the Campaign Group of left-wing MPs.

The Prime Minister had hoped to put a lid on all leadership speculation by saying that he would leave towards the end of a third term, but the idea that Brown and other leaders-in-waiting will hang on for Tony Blair to close the door is pretty far-fetched. Should New Labour scrape home in May, the "stalking donkeys" who were ready to start plodding last summer will be ready to do so again. All it would take would be for a couple of powerful union general secretaries to give the green light, and the "new" would soon vanish from Labour, and Tony Blair from 10 Downing Street.

The other scenario is altogether more chilling. A big majority, albeit on a massively reduced voter turnout would encourage Blair to shift Brown to somewhere rather less appealing than the Foreign Office. New Labour would continue on its weird odyssey, and Blair's eventual successor might only have a chance to survey the ruins.

The author is a member of the Labour Party's National Executive Committee