Most front-rank politicians make bad historians, at least of their own times. The perspective is too narrow, the need for self-justification too pressing, the memories too raw.
The late Roy Jenkins brought some of the detachment to his own consummately well-written memoirs, Life at the Centre, that he had deployed in his biographies of Asquith, Churchill and Gladstone; and Denis Healey's The Time of My Life deservedly delighted a large readership.
Jenkins had and Healey has wide intellectual interests outside politics, of course, and both were unusually adept at making serious autobiography accessible to a public not obsessively interested in day-to-day politics, the only sure-fire recipe for lasting popular success in this overcrowded genre. The books by Nigel Lawson and Geoffrey Howe were less compelling, perhaps, but remain serious and well above-average accounts of public policy in the Thatcher years.
But these were exceptions to a rule that applies as much to prime ministers as those who might have been but never were. John Major's autobiography, oddly, was probably the most enjoyable by a post-war prime minister. But except for the hardiest student of the second half of the 20th century, Ben Pimlott's biography of Harold Wilson will surely long outshine his subject's memoirs of office, just as Hugo Young's One of Us will Margaret Thatcher's.
The rule, of course, applies to autobiography and not to diaries, assuming they are not expurgated. Even if much of the work was done before the general election, Peter Mandelson has set a precedent by the sheer haste with which he has rushed into print, trumping his friend and sometime patron Tony Blair, at least on Blair's travails with Gordon Brown. But that hardly compares with the one set by Richard Crossman, the last-but-one time a Labour government fell from office.
Crossman remains the great prototype of the cabinet minister/diarist, and the sensation he caused when he came to publish was much more than a mere matter of big headlines in the serialising newspaper, the (then Lord Thomson-owned) Sunday Times. The concerted efforts made by the British establishment to suppress publication and the sheer shock to a then resolutely secretive system of the revelation of the inner workings of cabinet government underlined that the Crossman diaries were both an epoch-changing event and a lasting historical document of the first importance.
There followed Tony Benn and Barbara Castle, both of whom, because of the freshness and candour that can come only with contemporaneity, shed real light on the times they described. Alastair Campbell, of course, another genuine diarist, while not a cabinet minister, had the closest of ringside seats at the heart of government. Indeed, it's striking that the published diarists of cabinet rank have all – so far – been Labour. Alan Clark's diaries will certainly last indefinitely, but he was, (like another accomplished diarist, Chris Mullin) never more than a middle-ranking minister, and Douglas Hurd has fastidiously done no more than show his diaries to his authorised biographer, Mark Stuart. But given the newspaper-fuelled advances available, it's hard to believe that there isn't at least one minister in each of the present coalition parties talking into his digital recorder every evening or two.
That said, it is harder and harder to replicate the genuine excitement generated by Dick Crossman nearly 40 years ago. Despite the barrage of heavily spun assurances at the time that the Brown-Blair relationship was in much better shape than it appeared from the media, it became clear to any sentient journalist by the middle of the second Blair term at the very latest that the post-election memoirs would reveal that they were in fact far worse than had so far been reported. Mandelson has in one sense done no more than provide the first authoritative – and certainly vivid – confirmation that this was indeed the case. But the level of the dysfunctionality had become clear long before last week. The nature of modern media – and even more of the tribal machines which repeatedly fed it during the Blair-Brown years – has ensured that this central deformity of New Labour had largely been exposed.
Whether the book will last along with the best rounded autobiographies, written in a great deal more tranquillity than this one was, it is as yet impossible to be certain, not least because a review copy was unavailable in this distant location until today. Certainly while there is no reason to doubt, judging by the extracts, that it is the truth, it is highly unlikely to be the whole truth. Mandelson is moreover by no means a diarist in the Crossman – or, as Alastair Campbell has been understandably at pains to point out – even in the Campbell sense. But from quite early in his political career he has had the habit of writing long notes to himself soon after events he regarded as important, and it is safe to assume he has drawn on these in producing The Third Man. If nothing else, these documents – the Mandelson papers – are likely to be of concrete use to future political historians.
A final question, in the light of his hints that he would like to return to politics in the future, is whether he has also drawn a line under his own political career. Those who have pulled off memoirs before the end of their political lives have been very few and very much greater than he is – Churchill through most of his career and De Gaulle from Colombey-les-Deux-Eglises. It's hard not to believe this is the end. But of course, with Mandelson, you never quite know.
Donald Macintyre is the author of 'Mandelson and the Making of New Labour' (2000)