As Harold Pinter himself said on BBC Radio on the morning of the first night of this fiftieth anniversary production of The Birthday Party, the play is more pertinent than ever; two mysterious men knock on the door and take someone away. It happens all the time.

One can see why the first critics were mystified, though. Pinter’s language is both heightened and banal, his seaside boarding house setting grim and grimy, his characters an unprecedented (at that time) mix of caricature, nastiness and compassion. Those baffled, angry first night notices were not “disgraceful,” as one or two contemporary critics have piously asserted, but truthful testament to the shock of the new.

That shock is fairly well recreated in David Farr’s revival, which has a livid green lighting by Jon Clark, casting lots of Expressionist shadows on Jon Bausor’s filthily designed B&B with ducks on the wall flying against the receding perspectives. Stanley’s hosts, the monosyllabic deck chair attendant Petey (Alan Williams) and his mock-gracious, sexually underprovided wife Meg (Sheila Hancock) are grotesque seaside exhibits.

The delivery of the lines is slow and emphatic, Hancock in particular colouring each syllable with a strangulated wistfulness. Justin Salinger’s hapless lodger Stanley has grown into such inert sullenness that you understand fully a) why Sian Brooke’s sexy neighbour Lulu thinks of him as a complete wash-out; and b) why Monty’s men have come to remove him. His number’s up.

When Stanley meekly succumbs, after the blindman’s bluff humiliations at his own birthday party, he departs in a suit and red tie, curiously evocative of David Miliband and New Labour. You realise that the action is a metaphor of individuality and conformism, and that in his first play Pinter is announcing his great theme. Farr’s production takes us straight to another similar first play heavily influenced by The Birthday Party, Martin McDonagh’s The Pillowman.

The abiding vigour of this astonishing debut is honoured in Hancock’s glorious, self-deluding Meg, exchanging her headscarf and medical stockings for a rose-tinted gown on party night; and the sensationally effective performances of Nicholas Woodeson and Lloyd Hutchinson as the sinister apparatchiks, the one a nostalgic little Jewish monster, the other a quietly spoken Irish husk, a spaniel-like quisling swallowed in the great maw of political corruption and affiliation.

- Michael Coveney