The National bills it as a theatrical and imaginative response to the governing class, while in a strongly-worded programme note David Hare declares that his third recent play to draw on public events, is pure fiction.

But even those with little interest in the problems that beset New Labour under Blair will recognise that at least three of his characters bear strong likenesses to Tony, Tessa and Lord Levy.

The totemic figure, played with breezy north London vulgarity by Stanley Townsend, is Labour’s fund-raiser Otto. And if the cash for honours scandal sits lightly on his shoulders while he organizes handshaking encounters with the PM, the potential for corruption at the heart of his little empire is serviced with cynical glee by Pip Carter’s fixer in sly asides to the audience.

Tamsin Greig strides the corridors of power as a home secretary whose husband is causing political grief with his dodgy deals abroad, plus a teenage daughter with a drug habit, while Hare’s chief goodie is Nicola Walker’s left wing teacher, a disillusioned idealist set on repairing the damage done to the girl by a gang bang involving a muckraking journalist.

In Howard Davies’ slick staging, the scene is thus set for several melodramatic set pieces, not least a showdown in a shorts bar between Walker and Adam James as the self-serving journalist, sparked by a striking prologue from Gugu Mbatha-Raw making her NT debut as a Downing Street aide.

But the key scene, set in the Number Ten gym, is played out between Greig as the problem politician, resolved to hang on to her ministerial career, and Anthony Calf as the suave but ruthless prime minister in a power struggle that turns nasty when she starts winning on points.

Bob Crowley’s set design with busy metropolitan projections is likely to test the stage resources of the five regional theatres in next year’s welcome tour of the play.