Twenty-five years ago, Ayub Khan Din’s story of a mixed-race British Pakistani family premiered at the Birmingham Rep, to reflect the travails of culture clash and identity in 1970s Salford. Opening in the runup to Blair’s Britain, with its open door policy and Cool Britannia, it felt like a look back to a distant, more hostile past for first- and second-generation immigrants.

It now returns to the same theatre in a co-production between the Birmingham Rep and National Theatre and feels – perhaps depressingly – newly meaningful, as well as entertaining and zinging with fresh energy.

Magnificently staged and vigorously directed by Iqbal Khan, its script sings with comedy that has not dated. And it draws the mind to just how much, or little, has changed since 1971, and whether a family like the Khans would find any greater acceptance today in the place they call home.

Pakistani-born George (Tony Jayawardena) has been married to his white English wife, Ella (Sophie Stanton), for 25 years but still hopes to bring his six children up the Pakistani way, which means plotlines featuring circumcision and arranged marriage. He is both a clown and a tyrant and the domestic violence, when it comes, feels stark and central here – a good shade darker than in the Bafta-winning film.

His identity crisis is just as acute as that of his children. “This country not like our people,” he says. While they strive for acceptance from the wider world, George speaks about turning his children into good Pakistanis with a zeal that points to great anxiety beneath, anxiety which is amplified by news of war between East and West Pakistan, looming in the backdrop and threatening to unmoor him.

Each of the actors gives a piercing performance and their characters bring out different aspects of the story’s culture clash without becoming representative mouthpieces. Tariq (Gurjeet Singh) and Abdul, (Assad Zaman) discuss the white community’s rejection of them (“To belong to something …” says Abdul with yearning, after being mocked by work colleagues) while Noah Manzoor is adorable as the youngest son, Sajit, zipped up in his parka coat, showing obsessive-compulsive tics and quietly traumatised by the dysfunctions of his family. The other children are less fleshed out, from Saleem (Adonis Jenieco), the art student, to Maneer (Joeravar Sangha), the religious one, and Meenah (Amy-Leigh Hickman), the headstrong only girl of the family, but they bring comedy, and Saleem’s “vagina” sculpture – a key prop – has lost none of its shock effect.

There is humour in the tea meetings, too, between Ella and Auntie Annie (Rachel Lumberg), the neighbour and undertaker’s assistant whose morbid comedy brings some of the best lines.

Despite the sharp edges of its central subject matter, the production is alive with sunny energy. Susan Kulkarni’s costumes capture 1970s fashion with their zany palette of canary yellows, greens and oranges. Sound (designed by Jon Nicholls with composition by Felix Dubs) combines with video and lighting (designed by Bretta Gerecke) to fabulously heady effect.

Overhanging screens resembling large Polaroid snapshots show a moving album of photos. Classic Indian songs are mixed with bhangra and house in an exhilarating score between scenes, and the lighting is dynamic and vivid. The set (also designed by Gerecke) is a protean wonder too, with one corner morphing from a coal shed to the family chip shop in seconds, while a staircase is wheeled to the front of the stage with striking lighting to instantly reconfigure the setting.

The Khans emanate great warmth but without any sentimentality or schmaltz. It all makes for an explosion of a show that feels surprisingly, joyously, fresh, a quarter of a century on.

• East Is East is at Birmingham Rep until 25 September and at the National Theatre, London, 7-30 October.