It is still the great unanswered question of British politics. No, not "When will Tony Blair go?", but "What will the voters make of Gordon Brown?" This week's opinion poll from ICM, showing Labour nine points behind the Conservatives, will feel about as welcoming to the Prime Minister as the British weather when he steps off the plane from Barbados tomorrow.
The findings are not quite as grim as they were reported, but they are grim all the same, and they will help to set the tone for the coming political season. Labour, on 31 per cent, were said to be at their "lowest for 19 years". In fact ICM had all three parties tied on 31 per cent in September 2003, just after the Brent East by-election, which the Liberal Democrats won from the Government.
The difference between then and now, of course, is that the Lib Dems are lower while the Conservatives have hit the magic 40 per cent figure. It was reported to be the first time that they have done that in ICM's polls since August 1992, the month before the Great Rift Valley opened up in modern Tory history, when David Cameron skulked in the night behind Norman Lamont announcing Britain's pull-out from the exchange rate mechanism. That is true, with one important qualification to which I shall return in a moment.
The poll confirms that the strength of Brown's claim to succeed the Prime Minister is built on his reputation for handling the economy. It may be that most people respect him not because they think he has positively helped them to become better off, but because he has avoided the fate of most chancellors before him, and certainly most Labour chancellors, of making a mess of the economy.
The Government's reputation for economic competence is the key to judging how Brown as prime minister would shape up against Cameron. And that reputation is under threat, because a gap is opening up between the statistics (which show the British economy growing strongly) and the perception (which is of rising immigration and unemployment).
It is not so much the current influx of workers from central Europe that is the threat. It was the failure of ministers to predict its size that looks incompetent. There would not be nearly so much of a backlash against the Government if it had refused to play the numbers game in the first place.
It would of course be grossly unfair to Brown if he suffers from the current fuss about migrant workers. Immigration is a symptom of economic success, rather than a cause of economic failure. And if anyone is responsible, it is Ted Heath, who signed up for a common market in which all workers had the right of free movement. But it is Brown's problem now.
That is why Alistair Darling, the Brown ally whose current ministerial job I had forgotten, said on Sunday that there would be no "open door" policy for the workers of Romania and Bulgaria if they join the European Union as planned in January. Surely it is John Reid's job to shut the door in the face of these good Europeans? It turns out that Darling's Department of Trade and Industry would have to run any scheme to restrict the rights of Romanians and Bulgarians to work here, and so he is allowed to lean on the door too.
I suspect the political fall-out of the summer madness about immigration will be limited, however. The Poles and Croats have been able to come here for more than two years now: more have come than expected, but the problems they create, apart from keeping down the wages of the low-paid (which benefits many of the middle classes), have been minor. A tactical block on the Romanians and Bulgarians should stifle Tory opportunism. Besides, Cameron doesn't want to be accused of focusing on immigration again.
The Brown succession is still on track, therefore. And he has reserves at the bank of political credit on which to draw. As a new prime minister, he will be able to pick and choose those parts of the Blair legacy to accept and reject. If he does it well - and his strategic judgement has rarely been in doubt - he could deprive Cameron of the "time for a change" theme.
Above all, he should be able to coax back those Labour voters who took refuge in the Liberal Democrats and in non-voting over Blair's foreign policy. The most dramatic shift in this week's ICM poll was the shift from Labour to Lib Dem, possibly caused by the Lebanon crisis reminding those anti-war Labour voters why they dislike Blair.
Yet the clamour for Brown is strangely inaudible. Large parts of the Labour Party have given up on Blair, but they wait for the Chancellor to take over with feelings ranging from doubt to dread.
I mentioned above that this week is not quite the first time that an ICM poll has put the Conservatives as high as 40 per cent. Another ICM poll did the same last December. Then, the Conservatives scored 37 per cent on the standard "how would you vote tomorrow" question, but went up to 40 per cent when people were asked about a hypothetical election in which Brown as Labour leader faced David Cameron.
It is extraordinary, after all the bile heaped on Blair for those policies with which he is so personally identified, that the prospect of Brown seems to drive so many voters into Cameron's arms. No wonder that for some time now the political betting market has predicted a hung parliament next time.
Government by negotiation between Brown and Sir Menzies Campbell, two players of the long political game from Fife, hardly holds out the prospect of an exciting political renewal. It may not be so long after Blair goes that Labour people will look back with wonder at their golden age of large consecutive parliamentary majorities.
If they ask, when did it all go wrong, the answer will not be at the time of the Iraq war but some time around now. Is this the time for the party to decide that what it doesn't like about Blair are the compromises necessary to win elections?
That is why the possibility of a challenger to the Chancellor, namely Alan Johnson, the Education Secretary, emerging late in the day and seizing the crown at the last minute remains very real. A party that took a risk and surprised itself and the public might at least have a chance of persuading voters that it can offer creative solutions to new problems.
Those who are getting ready to howl for Blair's blood at the TUC and Labour conferences next month could do worse than devote even a 10th of their time and energy to worrying about why their party seems so ill-prepared to win elections without him, and why Labour's heir apparent pushes such a tiny bow-wave of excitement before him.
The writer is chief political commentator for The Independent on SundayReuse content