Just what kind of vision and audacity did it take to found the NHS?

Tim Price's uneven biodrama of socialist firebrand Nye Bevan offers most of an explanation - while failing to get under its subject's skin.

There's vision and audacity in director Rufus Norris' surreal staging, which plays out as a morphine-laced fever dream with Nye Bevan lying dying in a hospital he was responsible for building.

Designer Vicki Mortimer's rows of cubicle curtains swish back to allow Michael Sheen, in distractingly badly-padded pyjamas, to relive vignettes from Bevan's life.

Hackney Gazette: Sharon Small as Jennie Lee in Nye at The National TheatreSharon Small as Jennie Lee in Nye at The National Theatre (Image: Johan Persson)

There are physical lifts, spinning hospital beds, and even a Singing Detective-style song and dance number as the drugs take effect.

We see the poor miner's son stuttering and bullied by his headteacher, the joyous discovery of books in a Tredeger library with living bookshelves, fist-pumping forays into infiltrating elitist Town Hall power structures, war-time Parliamentary battles with Chamberlain and Churchill, and outrageous flirting with future wife and fellow MP Jennie Lee. (Sharon Small)

But between the flights of fantasy, Lee - and Small - are underserved by some stultifying front cloth exposition dumps over the comatose Bevan, as we learn he was unfaithful, Lee sacrificed her career, they lost a baby etc.

Hackney Gazette: Michael Sheen in Nye at The National TheatreMichael Sheen in Nye at The National Theatre (Image: Johan Persson)

The show more movingly evokes Bevan's defining relationship with his miner father, a recurring spectre whom he won't or can't comfort as he dies horribly of black lung, and who later guides his dying son through the vale of tears with his lamp.

The birth of the NHS feels shoehorned into the final half hour amid a projected backdrop of nay-saying doctors and their deeply conservative union.

A bouffed and pyjama-clad Sheen offers boyish charm, vulnerability and ebullience and is great at the physical transformations from child, to grieving son, to political disruptor.

But the epic storytelling works against a transformative psychological study; hints at Bevan's imposter syndrome, emotional avoidance, and rampant infidelity go unexplored.

Sadly too, amid shouty Parliamentary scenes that are played for laughs, we never discover why Nye was such an inspirational orator.

As a final projection hails the achievements of the NHS, it's hard not to think depressingly of how Bevan's trailblazing idea is now a sickly shadow of its former self.

Nye runs at The National Theatre until May 11.