Another day, another play about real-life politics. But unlike the turbo-charged plays of James Graham, who has made great theatrical capital out of showing the functioning of a minority Labour government clinging to power in the 70s (This House) and now a history of the Labour Party across the last quarter of a century (Labour of Love), Chris Hannan's What Shadows is a more sedate, endlessly discursive revisiting of the reactionary politics of Midlands MP Enoch Powell.
Also set across 25 years, it focuses in particular on his incendiary 'rivers of blood' speech that provided a cautionary warning about the dangers of immigration, multi-culturalism and identity politics, and then fast forward to find him an old, still embattled man, facing the ravages of Parkinson's disease and being challenged on the impact of that speech by a black Oxford academic. But if it feels at times more of dense dramatised history lecture than a play, it is given a powerful shot of theatricality by the riveting, monumental performance of Ian McDiarmid as Powell.
Part impersonation - the actor is barely recognisable - and part bold imagining, he dominates a discomforting evening that poses some big conversational questions. But the play too often feels just that: a conversation, and quite often a rather dull, dry one, as different viewpoints are ping-ponged back and forth.
The production originated at Birmingham Rep which has itself wrestled with big issues of cultural conflict, as when its 2004 production of a play called Behzti was cancelled after protests from members of the Sikh community that it portrayed. There it played in a large theatre that seats over 800; now it has been scaled back to the rather smaller (200 seater) Park Theatre, where it is luxuriously cast with prominent actors that as well as McDiarmid also include Joanna Pearce as Powell's wife and Nicholas Le Prevost and Paula Wilcox as a local newspaper editor and his wife who are their best friends, until the speech comes between them.