As The Times hits doorsteps this morning, many of our readers will be poised to cast their vote. Seldom in modern history can the British electorate have pondered an important political choice in weirder circumstances.

Do we any longer have a Government to vote for or against? We have a Prime Minister who has lost his grip on communications as senior and junior colleagues freelance their resignations or retirement plans. We have a Cabinet where some or all of the three great offices of state look vulnerable to an imminent and bitter wrangle about who should fill them: a Cabinet whose members - politicians who until yesterday helped to define the Government's personality - now desert, await the sack or declare their unwillingness to shift.

What will be the shape of a post-June 4 Labour Government, we cannot know - because it's pretty clear that the Prime Minister himself does not. Gordon Brown no longer has any power to insist; instead he will have to wheedle, deal, cajole and threaten. He may achieve a Cabinet dominated by his favourites; he may have to accept an armed truce with the Blairites, policed by Lord Mandelson. He may be ousted. He may himself quit; commanders are always going to fight to the last drop of blood, until they don't.

Such are the uncertainties. Voters inclined to cast their votes for Labour candidates today will have to swallow huge doubts about what they are saying “yes” to. How far this all is from 1997 when the nation had a strong sense - founded or unfounded - of who and what it was assenting to. Today we are invited to tick the box marked Mayhem; or perhaps the box marked Deadlock; or perhaps just Drift.

The hysteria of the past few weeks, led by the MPs' expenses scandal, and the pandemonium of yesterday, are only the culmination of a slow but relentless blurring of what the Labour Party means, lives for, stands for and promises in the 21st century.

I would argue that the blurring began as Tony Blair's ascendancy began to fade. Far from deriving from Mr Blair's strength, the effect derives from his weakness. Behind a galvanising personality and huge personal charm lay a void as to what, once the old of old Labour had been expunged, the new of new Labour really meant. Blairism never became strong enough to survive Blair. Brownism, meanwhile, has turned out not to exist. Now it may be Mr Brown himself who loses the battle for survival.

Or maybe not. Yesterday started in something close to Labour mayhem. By evening the breathlessness had begun to ease, not because of any change in the dismaying circumstances, but because one can only be dismayed for so long. After dismay comes depression, and depression can be a stable state. And it is in this that Mr Brown's last refuge could lie. Having canvassed on these pages last Saturday the possibilities of a palace coup - and still believing that this outcome is as likely as not by the end of next week - let me remind you how horribly possible is the alternative. The six most misleading words in the lexicon of politics are “it can't go on like this.” It almost always can.

The Queen will not ask Mr Brown to relinquish national leadership unless he loses the Commons. It is fantasy to suppose that in an Opposition no-confidence debate Labour rebels could tip the vote against him. Such a motion would be just as likely to frighten the sheep back into the fold, consolidate Mr Brown's grip on his party and steady morale. He can choose anyone he wants for his Cabinet next week.

The chances of an internal coup within the Parliamentary Labour Party are stronger. But what would the coup leaders be asking the led to do? To proceed immediately (Mr Brown's allies are whispering) to the guillotine of a general election.

I don't myself accept that a new Labour prime minister would have to call an immediate election. He or she could probably get away with naming the date (early next spring) and asking us for a breathing space to steady the ship of state, chart a course and develop the sustained challenge to the Opposition that the Tories deserve but have yet to face. There would be a fortnight's national squealing about constitutional outrage, and then we'd lose interest.

But Mr Brown's allies are encouraging the idea that no new leader could escape demands for an immediate electoral mandate. In which case more than 100 Labour MPs fearful of losing their seats whenever the election comes and whoever leads their party are being asked to forgo a year's income worth (with perks, as we now know) something approaching £100,000.

Reflecting on this after the immediate shock of the election tsunami about to engulf them, insurrectionist Labour MPs' brave yelps of defiance may die. Expect the tsunami. Expect the yelps. Expect the rumours of plots and maybe even the plots themselves. But don't be surprised if, in a couple of months' time as we head off on our summer holidays, we look back on this week as a strange and fevered time in which the Labour Party almost screwed up its courage to mount the challenge it knows it should to its benighted bully of a leader - and then, yet again, lost its nerve.

Mr Brown is not the cause of Labour's agonies, but a symptom. Rotting institutions get rotten people as their leaders. Always too cynical to put down the roots of confident belief, Blairism was more effective at breaking the party's continuity with its own past than at growing a new creed to replace it. We are left with a Cabinet of bedwetters: some bright and decent people among them - but where's the backbone, where's the beef? Their fate could be to become the third party; perhaps by as early as this weekend; perhaps never to return.

I watched David Cameron at Prime Minister's Questions yesterday. I wish I thought I saw a leader as much the master of events as Mr Brown is their plaything. But, though Mr Cameron has done well not to fall of his bike in the storm about expenses, there's still a wobble to the ride. He prays that Mr Brown will crawl from the wreckage this weekend, still Prime Minister, and carry on. There's a fair chance his prayer will be answered.

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