In 1960, Gore Vidal wrote a question in the form of a play: can principle ever survive politics?

It’s as relevant as ever, of course. But what makes Simon Evans’s terrifically performed revival fly is that it is brimful of the wit for which Gore — the man who once said “any American who is prepared to run for president should automatically, by definition, be disqualified for doing so” — was known.

The action takes place in a Texas hotel in which two presidential hopefuls are staying with their wives (Glynis Barber and Honeysuckle Weeks) while their (unspecified) political party chooses its White House candidate. Martin Shaw is Secretary William Russell, a kind of forerunner of The West Wing’s well-heeled, liberal Jed Bartlett. American actor Jeff Fahey is his Rottweiler opponent, Senator Joseph Cantwell.

It emerges that the ruthless Cantwell is about to publish his opponent’s medical records, which may cast doubt on Russell’s mental stability. And although Russell is the more principled politician, his campaign manager has also been doing some digging, and the two politicians face each other with information from the other’s past that could finish the other’s career.

Jack Shepherd is terrific as Hockstader, an ex-president kingmaker, while Maureen Lipman is on excellent form as the haughty yet grounded Mrs Gamadge, whose backing guarantees the votes of millions of women.

However, the real star is Vidal: Though the author, who died in 2012, rather loads the dice in favour of his preferred candidate, his play generates real tension and is written with the kind of wisdom for which any president would be grateful. Except, perhaps, today’s, about whom the title could only be used in extreme irony.