First Night: Now Or Later, Royal Court, London

Unmissable, but was it inspired by a Prince's gaffe?

Do you want to hear something good about Prince Harry, something that hasn't been spun by the Palace and that does not involve the armed forces or "extras" from the third or developing worlds? Well, I suspect that he may have partly – and wholly inadvertently – inspired a controversial new play of razor-sharp wit and explosive canniness.

One of the Prince's foibles, stupidity, was notoriously demonstrated in his faux pas of parading with a party of hoorays wearing a swastika armband. In Christopher Shinn's Now or Later, set on the night when the results of a US presidential election are pouring in, the son of the man poised to take the White House from the Republicans, has made a similar grievous gaffe. But that's where the dissimilarities begin. Prince Harry is not troubled by conspicuous intelligence, and his hormonal life is simple. John, Shinn's preppy protagonist, is gay, the survivor of a teenage suicide attempt and is very intelligent.

Premiered in Dominic Cooke's immaculately acted production at the Royal Court, the play is set in a hotel room. Under duress, John has joined his family and the entourage of party enforcers. Just as a micro-managed media campaign is achieving its goal, pictures on the internet are threatening to maim the first steps of the new administration. They show John at a "naked" party thrown by a left-wing female student at his Ivy League college. He'd been sickened by her support for a Muslim student group that wanted to change the university's freedom-of-speech policy. He despised her for her right-on contradictions and lip service in defence of fundamentalists. So he had gone costumed as Mohamed and, with the help of a dildo, had simulated being on the receiving end of fellatio. The enforcers have written an apology for John. But, as the minutes tick by and the impending storm intensifies, he needs persuading. To relent would be to strike a blow against free speech. To resist would be Oedipal revenge for years of paternal neglect.

Eddie Remayne is superb. Eyes glittering with wit and wounded sensitivity, he shows how John is both damaged goods and the goods. There's a wonderful moment when, after a phone call from his former therapist, he reveals that he thought it was going to be from the boyfriend who recently dumped him. His face fights a great dam-burst of tears and you ache for him.

Matthew Marsh is equally good as the burly president-elect, his sleep-deprived eyes darting little glances of calculation as he tries to manoeuvre his son into authorising the all-important apology. The play raises deep questions. Should liberals respect the religious views of theocrats who may abuse that right to smuggle through hateful political baggage? And how far should you misrepresent your post-election intents to gain power? Unmissable.