As police figures show racist crime soaring in the UK since the Brexit vote, it could scarcely be more timely to stage a dramatic portrait of Enoch Powell, the Tory MP whose “rivers of blood” speech in 1968 proved a watershed in the public discourse of what was then still known as racialism. More apt still to present it at Birmingham Rep, the major regional producing house nearest to Powell’s constituency in neighbouring Wolverhampton.

Playwright Chris Hannan alternates in the first half between 1967-8 and 1992 (focusing on ’92 after the interval), when two opposing academics collaborate towards a book on national identity. This concept is the keystone of Hannan’s piece: the Sixties thread, too, shows not only Powell’s public face but also the tensions with his oldest, Quaker, friends, along with scenes from the radical Nineties scholar’s mother’s Wolverhampton boarding-house and a neighbouring widow who claimed to be the last white occupant in the street.

Director Roxana Silbert gives generous rein to her whole cast. Paula Wilcox doubles strongly as the widow and the adoring but moralistic distaff side of the Powells’ couple of friends, and Rebecca Scroggs is impassioned but intellectually hectoring as historian Rose, building to a climactic scene in which we yearn for her to best Powell in an interview but know that she cannot. Powell was one of the most prodigious minds of his generation, but allowed political career frustration to seduce him to the dark side... you can’t help thinking in such terms when he is played, marvellously, by Ian McDiarmid (with only a couple of fleeting instances of Star Wars Emperor-voice).

The conclusion is that, whether in terms of race, domicile, or in the face of physical or mental deterioration, my identity is what I believe it to be, because I say so. Powell’s flaw was to believe that he could likewise declare upon who we collectively are. This was always going to be problematic, as he attempted to speak for the common Englishman by quoting Virgil. Hannan is canny in offering no doctrinaire answers but asking the questions with impartial rigour, and Silbert and her cast – praise is also due Bríd Brennan doubling as Powell’s wife and the older, wiser historian – make a talky play compelling. Also, cheekily, the interval music is “Get Back”.

Written for the Financial Times.