Nevertheless, the doubt did continue to nag — and I fully understood what even David Cameron's closest supporters meant when they said that it remained for him to "close the deal". Somehow, for all his charm and appeal (and his undoubted success in "detoxing" the Tory brand), he just did not command the stature and authority that Blair seemed to do back in 1997. Probably this should have led me to conclude that, despite all the evidence pointing to a Tory victory, one vital ingredient was missing. The voters may have wanted out of impatience or exasperation to toss out a Labour government but they gave no sign of being anything like so sure about what they wanted to put in its place. Was not the truth of the matter that, if the Conservative polling lead necessarily looked pretty wide, even its durability could not banish the suspicion that it was also distinctly shallow?

Curiously, the first time that suspicion took root in my mind had nothing to do with Cameron or his Shadow Cabinet colleagues. The Sun, you may recall, had first declared its conversion to the Conservative cause last September (on the same day that it was also reporting Brown's speech to the Labour Party conference) and a month or so later it braced itself to deliver what it plainly took to be a knock-out blow. Although he does not attend military funerals, the Prime Minister, like his predecessor, has always made it a rule to write to the bereaved families of service personnel who have lost their lives, whether in Iraq or Afghanistan. The Sun, of course, knew this and, having presumably been offered it by a reader, reproduced one such hand-written letter — complete with mis-spellings and ink smudges — on its front page along with the resentful comments of the recipient. The next day, Downing Street put a phone call through to the woman concerned so that the Prime Minister might offer a personal apology for any apparent, though unintended, discourtesy. But the Sun was already a jump ahead of the game. Anticipating what the Downing Street response might be, it had arranged for the incoming call to be recorded and was thus able to take a second bite at the cherry by offering its readers the transcript of the phone conversation between a contrite PM and a still indignant parent. I freely admit that I had at the time no notion at all as to how this bizarre incident would play with public opinion but I found the ultimate outcome both refreshing and reassuring.

There remains, it seems, a basic instinct for fairness among the British people, and the general popular reaction appears to have been that on this occasion the Sun had gone too far. It was not just the element of entrapment, though the recording of the phone call in the US would have been a criminal offence. Equally objectionable was the pillorying of the PM for his handwriting. You do not have to be a walking encyclopaedia on Gordon Brown to know that, as the result of a teenage rugby injury, he lost the sight of one eye, which causes him to write with a thick-nib felt pen that he does not always wield with much skill or grace. Hence the smudges and the crossings-out on the letter that may or may not have disguised actual spelling mistakes.