The Human Body: Keeley Hawes is terrific in this worthy fusion of NHS homage and Brief Encounter

Keeley Hawes and Jack Davenport in The Human Body
Keeley Hawes and Jack Davenport in The Human Body - Marc Brenner

Whatever vitamin supplements or other treatments Jack Davenport and Keeley Hawes are taking, can they share the details because they’re looking radiant. Back on stage for the first time in almost 20 years, Davenport, despite greying hair, seems barely altered since his 1996 TV breakthrough in This Life, while Hawes is so unblemished you’d swear she’d never set foot under the hot Corfu sun for The Durrells.

Their unfurrowed appearance is even more impressive given that they’re having subtly to strain nerve and sinew to win us over to a play by Lucy Kirkwood – revisiting the founding of the NHS – that urgently needs a scalpel to cut back excess flab. Something to counter motion sickness might help too: this overlong swansong production by Donmar artistic director Michael Longhurst (with Ann Yee) uses the revolve like a Les Mis tribute night.

One usually suspects a play lacks a raison d’être when its title sounds nondescript. In fact, Kirkwood’s drama of ideas and passions is valid – rewinding to post-war austerity Britain to depict hard-won new beginnings on the home front and the political sphere. Still, The Human Body hardly sets the heart a-flutter and, oddly enough, the superior title (in all ways) that the evening knowingly calls to mind – to the point of using live cameras to conjure black-and-white cinematics, complete with stirring strings – is Brief Encounter.

Hawes plays Iris, a decent, upright Shropshire doctor and would-be Labour parliamentary candidate who’s fully behind Bevan’s health revolution, in contrast with her jaded, war-wounded GP hubby Julian (Tom Goodman-Hill), who resents the financial and socialistic implications. That marital malaise is intensified by her chance meeting on a train (increasingly steamy locomotive trips to London ensuing) with Davenport’s dishy George, a local lad turned Hollywood matinee idol.

The latter, unhappily married too, is debonair and not on the same page of principle – he didn’t serve during the war, but proselytises persuasively for the health benefits of the silver screen, with an eye on restoring Iris’s physical sense of self too. Torn between marital drudgery and impossible escapism, Iris turns, after no little agony and something like a nervous breakdown, to forging her own noble, self-sacrificing path.

Jack Davenport in The Human Body
Jack Davenport in The Human Body - Marc Brenner

Kirkwood has done her homework, dropping in neat period details, be it to lodgings offering “hot water” or gendered assumptions in a Pathé news pastiche. She has welcome wit but can incline to convolution. And this piece is at its best when, slowing its whir of scenelets (entailing much intrusive stage-management activity), it keeps it simple: romantic overtures in a restaurant, devastating marital rejection, a sudden impassioned speech in defence of progress.

There’s no faulting the leads: Hawes brims with admirable decency and pained yearning in a bright-eyed Celia Johnson-esque fashion, while Davenport is armed with watchful charm and a seductive bedside manner. Goodman-Hill impresses too as the irascible but not irrational Julian, warning of NHS failures ahead, and he works his socks off (as do Siobhan Redmond and Pearl Mackie) in a cluster of supporting roles. All the same, it’s not only they, you feel, who are left in need of a quiet lie-down afterwards.

Until April 13;