So what are we to make of Lord Butler?

This week sees the reintroduction of two of the best-loved features of late-20th-century politics: by-elections and an official report. Usually the government of the day is damaged by both. Sometimes the damage is permanent, as it was, for example, with the Orpington by-election or with the late Lord Wilberforce's report on wages in the coal-mining industry. Both helped the Conservatives lose the general elections of, respectively, 1964 and February 1974.

More often, however, the news of the week becomes yesterday's cold mashed potato, in retrospect hardly remembered at all even by those, such as the readers of this column, who eat it eagerly on its first appearance. Will the report of Lord (formerly Sir Robin) Butler have much political effect? The consensus of the broadsheet press is that it will.

Lord Hutton's earlier report, on the death of Dr David Kelly, surprised most people. For weeks in a hot August in the Law Courts - what counsel to the inquiry, Mr James Dingemans, called a "lost summer" - we heard of ministers and their aides, more of them aides than ministers, lounging on sofas in No 10, drinking coffee out of mugs (just as our beloved leader does) and plotting the downfall of assorted characters or institutions in the most indelicate language.

What was worse was that there did not seem to be any designated chairman of these meetings. No proper records were kept or, indeed, records of any kind. The distinguished judge was able to learn as much as he and, accordingly, the rest of us did because of the modern habit of sending text messages when, not so long ago, a fugitive and unrecorded telephone call would have served instead.

Lord Hutton himself was polite but chilly. He struck one as the kind of judge who would offer you a refreshing glass of sparkling Ulster mineral water before sentencing you to death. Few of us thought he would go quite as far as this, even if it is what he would have liked to do in a perfect world. We thought, rather, that he would criticise both sides, but the Government more heavily than the BBC.

As things turned out, the Corporation was treated in terms appropriate to a fraudulent company promoter at the Southwark Crown Court; while the Government was let off, not even with a caution, but more with an apology for having taken up so much of its members' valuable time. Certainly Mr Tony Blair left the court without a stain on his shirt.

The bill of health given to him and his colleagues was not, as it happened, quite as spotless as most of the newspapers agreed it was. For instance Lord Hutton, contrary to reports, was ambivalent about whether No 10 had "sexed up" the relevant intelligence dossier. It all depended, he said, on what you meant by sexing up. No matter. The overwhelming impression left on readers who had not read the report (any more, one is tempted to add, than the authors of some of the newspaper stories about it had) was that Mr Blair, Mr Alastair Campbell and the rest of the crew had been crowned with laurel leaves and paraded in triumph through the streets of London.

The citizens refused to believe it. They had, after all, read the evidence which Lord Hutton had heard. More likely, they had watched it being summarised or re-enacted on television. And they refused to accept what the judge had concluded or, rather, what the papers said he had concluded. They thought it was a "whitewash". Never, to my knowledge, has any report produced an effect so directly opposite to that intended, as much by government as by its author.

Lord Hutton is said to be surprised, and even a little pained, at this public response, Lord Butler is reported not to want to be like Lord Hutton. What this seems to amount to is not so much that he intends to ignore any perversity on the part of the public as, rather, that he is determined not to give them any occasion for such a response in the first place. He is resolved, that is, not to give the Government the benefit of any doubts that may be lying around.

Moreover, he has apparently interpreted his terms of reference more liberally than Lord Hutton was prepared to do. He has not chosen to regard military intelligence as a narrow matter. He has not quite taken the world as his parish, as John Wesley did. But he has, it seems, adopted the view that Mr Jack Straw's overruling of legal opinions about the Iraq war is well within his committee's competence.

If this is so, it must come as a surprise not only to Mr Blair but to the leaders of the other parties as well. For Mr Charles Kennedy refused to have anything to do with the inquiry in the first place. Mr Michael Howard first said Yes and then, like the traditional flirt, said No. But the original Conservative representative, Mr Michael Mates, remained on the committee in a "personal capacity", whatever that may mean precisely. Anyway, good for Mr Mates, or "The Colonel", as we old sweats sometimes call him.

Mr Howard's and Mr Kennedy's reasons for refusing to co-operate were more or less the same with both of them: that Lord Butler's terms of reference were too narrow and that a committee chaired by a former Secretary of the Cabinet would lean towards the government of the day, however hard it might try not to do so. And with Lord Butler there were additional reasons for apprehension. In the 1990s (he occupied his position from 1988 to 1998) he sometimes acted as Mr John Major's man-of-business. In particular, he was asked to investigate various "sleaze'' allegations of that decade. Notoriously, he pronounced a Not Guilty or, at any rate, a Not Proven verdict on both Mr Jonathan Aitken and Mr Neil Hamilton.

The criticism was not so much that he arrived at wrong verdicts as that he should not have been adjudicating on these cases in the beginning. Mr John Major should not have asked him and Lord Butler, awkward though this may have been, should not have complied with the request. The tasks were clearly of a party-political nature.

It is doubtful whether Lord Butler will go down as a great Cabinet Secretary. But then, can there be such a creature? As an Oxford philosopher once remarked: there can be a great racing driver, but can there be such a thing as a great taxi driver? It may be that Lord Butler has determined to make a name for himself in the autumn of his days as Mr Valiant-for-Truth. But again, he has never been happy about the changes introduced by Mr Blair and Mr Campbell into the civil service and into No 10. Mr Blair has now given him the chance to make this clear, even if in an oblique manner.