Chris Mullin, the amiable backbencher and sometime junior minister, does not appear in the index of Tony Blair’s memoir, A Journey. He is not in the index of The Third Man, Peter Mandelson’s insider’s tale, nor that of Alastair Campbell’s The Blair Years. To the talent at the top, Mullin was simply a vote and not a very reliable one at that. How lucky for the rest of us that he is so much more, as his second volume of diaries, Decline & Fall, reveals in the same engaging, clear-sighted way as his first, A View from the Foothills.

 This volume is a melancholy account of New Labour’s third and final term in office.    It covers his final years in parliament, a period spent entirely on the back benches, removed from the conventional political and parliamentary power structures. He is increasingly frustrated by the futility of his day job and alarmed by the growing distance between Westminster and the real world. 

Mullin’s supreme virtues are an eye for the absurd and an incorruptible independence of outlook. That he is a little vain about the latter is clear from the pleasure he takes in the friendly respect of other independent spirits at Westminster, regardless of their politics.   He curses the inhumanity of immigration controls and their impact on scores of his constituents, but is clear-eyed about the way the rules are sometimes exploited. And he observes how Blair’s passion for permanent revolution results in an unintended narrative of permanent failure.

Diaries, by definition, only ever cast a narrow beam of light. Mullin was rarely even in the same room as real power. But like all good journalists, he is always on the lookout for motive and, like the best storytellers, he lets us see for ourselves what it is.  It should be compulsory. It is an indispensable hangover cure for anyone who has ever been drunk on the idea of power.