Ever since Gordon Brown began his autumn political fightback and the opinion poll gap between the Tories and Labour started to narrow, David Cameron has faced a fundamental question from within his own party.
It is this. Why, in the teeth of a recession that was almost certainly exacerbated if not actually caused by Mr Brown’s stewardship of the economy over the past 11 years, was he not able to “seal the deal” and convert the Tories’ earlier advantage into a settled, potentially election-winning lead?
There are many explanations which I and others could give. The inexperience of the Cameron – George Osborne partnership when set against Brown and Alistair Darling is perhaps the most obvious one.
Another is that, for all their criticisms of Labour, the Tories have yet to articulate a clear and compelling alternative vision, either for the conduct of the economy or for Britain in general.
Either way, there is a growing fear in the party that Mr Cameron will somehow manage to end up a loser despite what, for him, ought to be the most propitious political circumstances for an opposition leader for many years.
One sporting analogy that has been drawn is with the 2005 Champions League Final, in which AC Milan contrived to lose to Liverpool despite being three-nil up at half-time.
With their opponents fighting back strongly and threatening to equalise, the Tories have somehow got to persuade the ref to blow the whistle before Labour can take it to penalties.
Which may be one reason why the Tories currently appear desperate to provoke Mr Brown into holding the election sooner rather than later.
It seems that not a month goes by at Westminster these days without a fresh bout of election speculation.
And with the Christmas silly season now upon us, it was perhaps inevitable that this would be another of those months.
It certainly cranked up a gear this week, with suggestions appearing on Tory blogs that Labour had block-booked hundreds of advertising hoardings for February.
The fact that this turned out not to be true only heightened the impression that the Tories were trying to fan the flames of the latest media frenzy.
There is a clear tactical logic to this from Mr Cameron's point of view. The darkest moment of Mr Brown's premiership so far was the point at which he decided not to hold an election in autumn 2007 after allowing his own ministers to stoke-up the speculation.
For a long time, it looked like he would not recover from that, but recover he eventually did, and Labour is now once again within spitting distance of the Tories in the polls.
So an obvious ploy for Mr Cameron is to try to turn spring 2009 into a re-run of autumn 2007 by generating another round of election fever, in the knowledge that it's a win-win situation for him.
If Mr Brown falls for it, the Tories will have the chance to end Labour's long hegemony. If he doesn't, it will be "bottler Brown" all over again.
Even so, there was little consensus among political commentators this week as to whether the speculation was Tory-inspired black propaganda or whether it is indeed actively being thought about in No 10.
One veteran political writer declared flatly: "There won't be an early election in 2009 for all the usual reasons, the most important being that Gordon Brown would lose it."
But another from the same newspaper maintained that, contrary to appearances, it is actually Mr Brown who wants the election to happen and Mr Cameron who doesn't.
"The reality is that while he says he wants it and Gordon says he doesn't, the opposite may well be the case," he said of the Tory leader.
There are two reasons being advanced as to why a Prime Minister who is still trailing in the opinion polls would choose now to have an election.
One is that the longer he leaves it, the worse the economy will get, although many economists think that there will be a recovery of sorts by 2010.
The other reason being put forward is that, despite being at least five points behind in share of the vote, Labour and Mr Brown could actually still win that way.
By a strange quirk of our electoral system to do with the relative distribution of votes, the Labour Party could be significantly behind the Tories yet still end up with more seats.
But the idea that emerging as the largest party while being behind on the public vote could constitute any kind of victory for Mr Brown is, in my view, nothing short of political insanity.
The Tories would argue, quite rightly, that they had the true mandate to govern and that Mr Brown had lost his.
More than that, by being seen to fail to deliver the will of the people, the entire political system would face a crisis of legitimacy that could send it into meltdown.
Of course electoral reform would have forestalled this, but Tony Blair chickened out of it and his successor seems no bolder in that regard.
The time for New Year predictions is still a couple of weeks off. As is my custom, these will appear in my first column of 2009 on Saturday 3 January.
But I will, nevertheless, lay my cards on the table and make two early ones.
The first is that there won't be an election in February, or indeed at any time early in 2009.
The second is that if I am wrong, and the Prime Minister is foolish enough to allow himself to be provoked into holding one, he will lose.
