On Behalf Of The People isn't a typical piece of Fringe theatre. For one thing, it's two hours long – but don't be put off by that, because it's engrossing and engaging the whole way through. It's performed in the round, in a bare-bones venue, a decision which brings the audience into the heart of the production and silently embodies the sense of community underpinning the plot. And most unusually of all, it's political theatre which doesn't lecture, but explains – which tells a story that genuinely stands a chance of changing hearts and minds.

On 1 January 1947, a sign was posted at the gates of each and every coal mine: This colliery is now managed by the National Coal Board, on behalf of the people. The nationalisation of this and other industries was a seismic shift in the economic order, and came hard on the heels of the social shock of the Second World War. Set in a town on the side of the Pennines, On Behalf Of The People shows the impact of these changes on a single mining family, beginning when the young Tom comes home from the army and ending as gruff patriarch George passes the mantle of leadership on.

The story may only span a handful of years, but they're tumultuous years – which, combined with a general theme of handover between the generations, lends the production an epic feel. Ray Castleton's script offers lofty insights too: into the way British society was re-shaped by the experience of war, and the fears and injustices which drove the programme of nationalisation. But it also shows that this wasn't a panacea. The downside of the new order is sensitively explored, and one touching scene between George and Tom's girlfriend shows how an all-powerful union could be every bit as cruel as a callous employer.

This historical education is delivered subtly, and neat set-pieces – a political meeting here, a family gathering there – offer opportunities to talk directly to the audience without breaking the illusion of theatre. But the family story is every bit as as important, and moves through several phases over the course of the play. There are secrets and tensions, and deep unspoken pain, and Connie – George's wife, the mother of the family – needs all her powers of comfort and persuasion to keep the people she loves together. The whole cast is strong, but Roy Ashcroft puts in a particularly moving performance as George, a man who's lost a hoped-for legacy but doesn't let that bitterness overcome him.

Charlie Kenber's direction is technically superb; the audience sit round all four sides of the stage, but I can't remember a single moment when I felt the actors had their backs to me. There's a constant sense of bustle and industry, with set and costume changes made into spectacles of their own, and apparent small details become telling highlights – as when a bright-red scarf, brought home by Tom from his service in Italy, hints at the colour he's bringing back into his lonely parents' life.

On Behalf Of The People works on two levels: as a still-relevant study of political and social history, and as a family saga filled with characters who make you care. It's come to Buxton near the end of a successful tour – catch it if you can while it's here.