That Alan Bennett’s a clever old thing. Even after all these years he seems as cosy as a pair of worn-out slippers and yet his plays always have a unique sting in the tail. With “People” his ability to crystallise something we’ve all felt even if only dimly remains undiminished.

Here it’s the heritage industry, where three of the stately women of England bicker over plans for their ancestral pile. But in reality his subject is age in an England where every thing and every one is getting on a bit, soon no doubt to get a free National Trust membership with their Rail Pass.

As a nation he sees we’re trying to hang onto the past by commodifying it, but Alan the master trend-spotter warns this is only a temporary solution. The future’s already here, and its hastily scrawled Pompeian graffiti is already (think Banksy) the stuff of museums.

With a powerful nod to the changes in women’s roles (one sister’s an ex-fifties Barbara Golen-type model, one an archbishop-in-waiting and one a proletarian by-blow of an aristocratic liaison) we see the past, present and future in terms of three stereotypes, a Downton Abbey without soft focus or blinkers.

In Bennett’s Three Sisters “heritage” is something that’s simply about resisting, or not even acknowledging, change, and the faux-celebratory nature of the play’s apotheosis where technology is harnessed to a wallowing nostalgia rings chillingly recognisable with its apparently cheery message; we want life to stand still while it has a horrible habit of changing and moving on. That’s life, he says. Get over it. Meanwhile the heritage industry’s no more than a form of posh porn.

This production is suitably starry in homage to our favourite living playwright. It’s also a wonderful opportunity to see the legendary Sian Phillips as eccentric ruin Dorothy Stacpoole revitalised by a nostalgic looking-over.

Selina Cadell (a regular on Midsummer Murders) is powerfully imposing as the archdeacon sister June. But for me the star is Brigit Forsyth, always remembered as Bob’s fiery fiancée in The Likely Lads and here still obviously at the top of her game as Iris the shambling “companion” and unacknowledged half-sister of the posher sisters.

A National Theatre production, this is a wonderfully celebratory debut for the new Rep. I look forward to their next hundred years.

People runs until September 21. For tickets go online at Birmingham-rep.co.uk or phone the box office on 0121 236 4455