This should have been a diabolical marriage made in heaven, the firebrand left-wing playwright on the last of the Tory grandee prime ministers, the showman politician bestriding the National's proscenium stage. At first all bodes well in Howard Brenton's Harold Macmillan biodrama. Jeremy Irons shuffles on as the older Mac lamenting that he always had trouble with his teeth: "Bad teeth in politics are not good. It got a lot worse when television came in." Eden's teeth, on the other hand, were "dazzling". He gets a big laugh, but it was actually in those first minutes I began to fear that Brenton and Irons were getting things wrong.
In the first place, to niggle, Eden had not dazzling, but buck teeth. They were, according to Piers Brendon in The Decline and Fall of the British Empire (1781-1997), the subject of a joke cracked by Churchill, to the effect that he feared an outbreak of myxomatosis would leave his foreign secretary vulnerable. In the second, the speech suggests that Macmillan was uneasy in front of cameras. Yet by 1962 he was so confident on television that he began one PPB by showing the TV crew and self-deprecatingly complaining about "the camera's hot, probing eye".
Brenton's Macmillan says when he became PM he had his incisors capped and learned to play the "tart"- as if that was some kind of problem to him. This is surely nonsense. Even today, it is a pleasure to watch clips of Macmillan hamming it up as the last Edwardian. Irons, however, gives a humourless interpretation that lacks Macmillan's greatest asset, his charm.
Meanwhile, in his own pensionable years, the writer of The Romans in Britain and Pravda asks us not to see through Macmillan's charm but to feel for the inner man. It is never clear on what grounds Supermac deserves our sympathy. Possibly Brenton buys his mother's assessment of Harold as a communist, a gibe based on an early book in which he suggested nationalising coal and gas. In his interpretation, Mac is a pragmatist at worst, the honourable fall guy in the Profumo affair and unfairly ridiculed by the "drunk" Peter Cook. The Night of the Long Knives, in which Supermac sacked a third of the members of his cabinet, is tactfully left unmentioned. Nor is there anything about the stitching up of his friend and natural successor, Rab Butler. Macmillan will be watching from above and thinking he got off lightly.
Brenton is more convincing portraying the Tory leader as psychologically damaged goods, knocked about by Nellie, his overambitious American mother (a two-dimensional Anna Carteret), and then by his wife, Dorothy, who wants to be the PM's escort yet cuckolds him for decades with Bob Boothby (good work by Robert Glenister as that nasty piece of work). "I didn't realise the role of an unfaithful wife is to sound like one's dead mother," says Macmillan, in case we had not made the comparison.
As Dorothy, Anna Chancellor has a struggle explaining her strange choice of men. Bob, she says, makes her feel alive. She must have been reading some very trashy fiction.
The play's main insight is that the Somme changed Mac for ever, that it knocked the stuffing out of him - though there did not seem so very much there in his Eton days - and replaced it with a survivor's feeling of unworthiness when it came to claiming his destiny. The enduring trauma of the First World War is conveyed theatrically by having Pip Carter as the young, uniformed Macmillan hang around on stage, not doing very much, through the rest of the play.
Actually, this is not as clunking a device as it sounds. Nor is it, all in all, a dull night out. The familiar historical pageant is very well staged by Howard Davies, who economically whips up the Battle of the Somme and later crashes a plane on stage, leaving it ablaze. There is some good (if irrelevant) dancing, and a funny impersonation of Churchill as a giant toad by Ian McNeice. But at heart, the play is as cautious as its conclusion that Macmillan, though tarnished silver, was silver all the same and bore "the hallmark" of a "democratic politician". Only in the Suez sequence - in which we are asked to make comparisons with the Iraq invasion - does it really grip.
Episodic rather than fluent, Never So Good is not so much a play of events, dear boy, events, as one damn thing after another.
Andrew Billen is a staff writer for the Times
Pick of the week
The Last Days of Judas Iscariot
Almeida Theatre, London N1
With telly's Jesus Christ, Joseph Mawle, as Judas.
Barbican, London EC2, from 9 April
Clytemnestra and Elektra appear before the South African Truth and Reconciliation Commission.
They Shoot Horses, Don't They?
Citizens' Theatre, Glasgow, 9-12 April
They dance till they drop in this new adaptation of Horace McCoy's book.