Who would have thought that the battle between champions of old-school socialism and contemporary identity politics for the post of General Secretary of Unify, a fictitious British trade union, would make for such riveting reading?

Nayan Olak and Megha Sharma have little in common save their skin colour. He is the son of corner shopkeepers, who started work on the factory floor at 16 and is now the union’s Head of Workplace Disciplinary Actions.