Stephen Pollard: What has happened to the David Blunkett I knew?

In all my conversations, I have found him to be honest and decent. But he has changed

It is almost always a mistake to second guess the conclusions of official inquiries. Rarely do they live up - or down - to the pre-publicity. But unlike the case with most such documents, Sir Alan Budd has already given us a sneak preview of his report with the publication last week of the so-called "timeline" behind the curious incident of the nanny's visa and the Home Secretary's private office.

It is almost always a mistake to second guess the conclusions of official inquiries. Rarely do they live up - or down - to the pre-publicity. But unlike the case with most such documents, Sir Alan Budd has already given us a sneak preview of his report with the publication last week of the so-called "timeline" behind the curious incident of the nanny's visa and the Home Secretary's private office.

Indeed, it was the pre-publication revelation of an e-mail from the Immigration and Nationality Department (IND) in Croydon to David Blunkett's office, which talked of having processed the visa application with "No favours, but slightly quicker", that in the end did for Mr Blunkett. We await Sir Alan's findings today for a fuller account of the comings and goings of the various pieces of paper. But as Mr Blunkett's biographer, I have been struck by one particular aspect of the affair.

I have spent three years studying David Blunkett's life. I have spoken to friends, colleagues, family, opponents and acquaintances. One thing has been mentioned above all others: his astonishing memory. I have heard from people who had one conversation with him, sometimes a decade or more ago, who have then met him again to discover that he can recall their previous exchange in exact detail.

It is his memory, above all else, that has enabled him not merely to compete with sighted ministers but to outperform them. And yet, when he resigned on Wednesday, Mr Blunkett told Andrew Marr on the BBC that "we didn't have a recollection, I don't just mean me, but throughout the system, of the letter [about Ms Casalme's case] actually being put into the system".

Come again? Forget his officials' involvement for a moment. Perhaps some of them really are as monumentally incompetent as some - not least the former Home Secretary himself, in his interviews with me - allege. We will need to wait for Sir Alan's findings to form a judgement on their involvement.

But there is already one element of the affair which is self-evidently preposterous. According to Mr Blunkett's explanation, he forgot putting into his red ministerial box a letter about the visa application for his own son's nanny. I am unable to comprehend how such an explanation is remotely possible. This is a man who can recall trivial conversations from 20 years ago with constituents about refuse collections; with a memory so powerful, its like has never before been seen in politics. And yet he forgot, he says, that he put his son's nanny's visa application into the system.

Pull the other one.

So what is going on? I thought I knew the man. In all my research, and in my conversations with him, I have found David Blunkett to be honest and decent. He has long valued his reputation for straight talking. But he has changed.

Once again, it is not the act itself that is necessarily the real problem but the cover-up. If Mr Blunkett had stood up and said, on the day after the allegations were first made, that there had indeed been special treatment, but that it was, after all, for his own son's nanny, then maybe he would still have had to resign. But he would have done so with his head held high, and with the understanding of most people. All he would have been guilty of was putting his family first.

Instead, he made a statement that, clearly, was not even remotely true. His office did not, we can already say with certainty, process the visa application off its own back. It did so because the Home Secretary alerted them to it. The allegations of bullying are a distraction. According to some reports, Mr Blunkett ran a regime of fear. He has been guilty of significant mistakes; but there is another agenda at play here. The former home secretary inherited a department that was a byword for inefficiency and incompetence, and ordered a large scale clear-out of the dead wood. The bullying allegations are the belated response, and deserve to be treated as piffle.

The real problem is the visa story itself, which stems from the influence exerted over David Blunkett by Kimberly Quinn, a woman who with every passing day emerges as a more unsavoury character. Mr Blunkett is rightly being held responsible for his own actions, but he became a different man when he began his relationship with her. At the very least, the old David Blunkett - the pre-Fortier version, if you will - would have been alive to the political suicide inherent in trying to cover-up his actions. But his judgement became so clouded by love he behaved like a different man.

I believe there is a pattern in his behaviour, post-Fortier, that also explains his recklessly frank comments to me about his Cabinet colleagues. He lost the judgement that had served him so well for his 34 years in politics, and behaved as if he had no care for the future, only for doing what his gut instinct told him he needed to do at the time. That meant not only helping to secure a visa for his son's nanny, but also letting off steam about his colleagues.

David Blunkett was not the first, and will not be the last, person to be brought down by falling in love with the wrong person.

'David Blunkett', by Stephen Pollard, is published by Hodder and Stoughton