What will happen to Labour when it loses the coming general election? We in the political world have been so fascinated by the uncertainties surrounding the handover from Tony Blair to (we suppose) Gordon Brown, that we have taken our eye off something more important for Labour, coming down the track behind. The odds are now that though the Chancellor may get his mandate from his party, he will not — when the time comes — get it from the electorate. What would then be in store for him, his party and his rivals?

These should be the big questions for those of Mr Brown’s senior colleagues who contemplate throwing their own hats into the ring. If they duck the challenge this time, how long will they have to wait until a next time, and what might be their chances then, compared with now? How long in the wilderness if they make an enemy of this most unforgiving of men? What will remove him, and will a postBrown Labour Party be a hospitable place for a David Miliband, a John Hutton or an Alan Johnson? What will they inherit?

My opening question rested on two premises: that a general election is coming, and that Labour will lose it. The first is certain, yet closer in our diaries than in our thoughts. A parliament cannot run beyond five years and usually runs for four; and we are two years in already. Assuming Gordon Brown does become prime minister this summer, the hoped-for “Brown bounce” could tempt him to chance his arm and go for a popular mandate next year. This Christmas, if Labour is close to the Tories in the polls, the new prime minister may be seized by a nightmare in which the Ghost of Christmas Yet To Come shows him a 2009 election where he rues the day he funked it in 2007-08.

Do not, therefore, rule out an early election, though we may doubt Mr Brown is that sort of a gambler. Otherwise — and if (as I predict) a Brown premiership fails to refresh Labour’s chances — an election in 2009 might be postponed a year. Mr Brown may end up simply hanging on as long as he can, as John Major did. So, facing Mr Brown’s potential rivals is the prospect, if they back off this time, of between a few months and a couple of years in Cabinet posts while a turn-of-the-century Labour Government heads dispiritingly for the buffers — that is, if the bookmakers, and the Parliamentary Labour Party’s own gloomy instincts, are right.

Are they right? That Gordon Brown is not capable of winning the Labour Party a fourth term in office is, of course, a big assumption. Forgive me, but I’m simply going to make it.

Sometimes I worry lest, immersed in my world of Westminster gossip and policy debate, I may lose touch with the mass of the electorate whose judgments are more instinctive; I ask myself whether the picture I see may be diverging from those of the electorate, who will have the final say. But I heard last week from a most unpolitical friend who, for £75, had agreed to take part in a forum organised jointly by the Equal Opportunities Commission and the Fawcett Society, to examine and discuss the problems of single mothers. On arriving the young mothers were told they were to have a special guest. It turned out to the Chancellor of the Exchequer.

My friend, who had not been unsympathetic to Mr Brown, had until then only seen him on TV. She said he was a dreadful disappointment. In fact she was shocked by how bad he was. A forced smile, a prescripted announcement, for which this visit and these women were really just the media frame, and an apparent inability (or disinclination) to listen to or engage with what any of them were saying, answer their questions or show openness to their ideas and testimony left her feeling cheated and angry.

Her response will in time spread through the electorate. Mr Brown is set to become better known, and for a politician whose appearance is confounded by the reality, the consequences of becoming better known are bleak. People think Mr Brown, though wintry, is straight-talking and brave. The truth is that he is indeed wintry, but that he is also shifty and timid. Voters will hate this when they find out.

So what will happen, when Labour loses? I doubt Mr Brown will volunteer his resignation. Both publicly and to himself, Mr Brown will blame his defeat personally on Tony Blair. There will be some force in the argument that after 11 years of Blair, after the Iraq war, after the vapidity and the spin, a year or two was not enough for Mr Brown to rebuild and rebrand his party. He will apologise handsomely for the defeat, remind us that his predecessor bequeathed him a Tory lead in the polls, suggest that Mr Blair left too big a mountain for him or the party to climb in a short time, pledge himself to rebuild Labour in opposition, assure Labour members that David Cameron and his “new” Tories are a giant windbag that a few sharp years (or less) government will soon prick, and invite the Labour Party to entrust him with that task.

On balance, I think the party will. Labour’s history betrays no taste for regicide, and many will think it hard on Mr Brown to kick him aside after only one defeat. So he will stay. And in opposition — robbed of the only thing he does do well, — which is to sound as though he’s running something — he will prove a failure. But this may not be definitively shown until the election of . . . well, do the sums: about 2013-14, I reckon. OK to hang on a bit, then, David, John, Alan?

But say I’m wrong. Say that in the aftermath of defeat in the coming election, the Labour Party panics, decides it got it all wrong — wrong about the Leader, wrong about direction, wrong about the way to win — what then? Here, Mr Brown’s potential “modernising” rivals must face a most unwelcome fact. If Labour ditches Gordon Brown in a few years, they won’t be reaching for the likes of a sleekly metropolitan moderniser such as David Miliband, the Environment Secretary. They will descend into a bitter civil war in which the voice of the Left, and of “old” Labour will be stronger, not weaker, than it is today. From such circumstances, only Alan Johnson (from among today’s possible contenders) might just be able to extract advantage, but I doubt it. Association with Labour’s years in government will be poisonous.

Look at the face (so far as a crowd of rebels can be said to have a face) of the 95 backbenchers who voted against Trident this week. I happen to agree with their argument. But I do not recognise in this gang of mostly left-of-centre exemplars of a party that has certainly not learnt (as Tony Blair once hoped) to love Peter Mandelson, a mood that would want to replace a defeated Mr Brown with something more right-wing. In nostalgia for the old days of CND marches, I do not see the ingredients of a new Labour renaissance. Wednesday’s rebels were not the shock-troops for a Miliband leadership bid in 2009.

No, the best hope for those who do not want new Labour to be cast aside in favour of old Labour or (more likely) a long and confused internecine struggle is that Mr Brown stays on in defeat.

Now — the spring and summer of 2007 — represents the best and probably last hope for any leadership contender who calls himself a Labour moderniser to reach for the crown. If not, it will have to be Brown. And he will lose the general election. And after that, in Opposition on the other side of that defeat, only Gordon Brown would have any chance of holding the new Labour line.

There is, of course, one possibility I have overlooked. This is that Gordon Brown might actually win the coming general election. I said that was unimaginable. His potential rivals, however, might care to imagine it. I hope that cheers them up.

So if you’re ever going to go for it, David, John, Alan, go for it now, not next time. There isn’t going to be a next time.

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