What do we remember of Harold Macmillan, the Conservative prime minister during that strange interregnum between the Suez Crisis and the first post-War Labour government of Harold Wilson? One Harry followed another, but the world had changed: we lost a grip on an Empire but failed to adjust to the new European democracy and the loss of privacy.

Howard Brenton’s Never So Good – the title invokes Macmillan’s famous phrase, usually taken as an over-smug motto for the era, “most of the people in this country have never had it so good” – is a fascinating chronicle play that is remarkable for its breadth of interest and lack of attitude.

That sums up a faint sense of disappointment in Howard Davies’ production that nonetheless implies the very interesting theory that politics is no place for human decency. “SuperMac” as we came ironically to know him after a newspaper cartoon, was the first public figure to be openly lampooned on the contemporary stage, in a sketch in Beyond the Fringe.

Jeremy Irons makes much of this moment, otherwise suggesting a character of almost blotting paper inertia, the very opposite of Brenton’s shark-like creation with David Hare of Lambert Le Roux, the Brechtian anti-hero of Pravda. We see Macmillan taking part in the Eton wall game, experiencing the horror of the trenches in the First World War, sidling, as of right, into politics, dealing with the Suez catastrophe, absorbing the Profumo scandal.

Irons’ Macmillan bares his teeth for the first and last time in the play in his bitter denunciation of the satirist Peter Cook as someone who knew nothing about the realities of life or politics. Brenton, the most gloriously gifted and “theatrical” fringe playwright of the late Sixties – his mantra was one of disrupting the spectacle, destroying the art form he adopted, rather like Shaw - lost his political faith with the death of Communism.

His recent plays – Paul and In Extremis – have been about the survival of spiritual faith in a secular world, and Never So Good is similarly slanted, though the script lacks any argument to support, for instance, Macmillan’s tacit approval of his wife Dorothy’s (Anna Chancellor, “Duck Face” in Four Weddings) affair with Bob Boothby (Robert Glenister).

At this stage, you start thinking that the play should be about Anthony Calf’s tortured, pathetic Anthony Eden, the prime minister Macmillan replaced. The fact that Brenton and Calf make Eden so interesting is a tribute to both. But it does rather highlight the flabbiness of the whole enterprise: so Macmillan was a human being, what else is new?

Maybe that’s the point. Political drama comes of age, shock horror. The one palpable dramatic ploy, that of shadowing the older Macmillan with his younger, idealistic self (Pip Carter) is woefully under-exploited.

Still, Clive Francis, unrecognisably transformed as Dwight Eisenhower, Terrence Hardiman as Neville Chamberlain and Peter Forbes as Selwyn Lloyd (a much more interesting figure than this cartoon outline) all bring an era of nervous political transition to fascinating life. But the central character remains less compelling than Hugh Whitemore’s version – courtesy of Edward Fox – in the more pointed, but nostalgia-drenched A Letter of Resignation ten years ago.

- Michael Coveney