It's intriguing watching a play about England's attitude to politics when a political crisis is breaking beyond the theatre's doors. Outside this elegant, incisive production of a new piece by first-time playwright Simon Woods all the talk was of Brexit and Boris Johnson's blustering attempts to prorogue parliament.
Inside, on Hildegard Bechtler's cream-walled set, which perfectly evokes a certain kind of barebones upper-class kitchen (complete with Aga), we are whisked back to May 1988, when Mrs Thatcher's government is in the process of passing the notorious Section 28 to the local government bill, which banned teaching about homosexuality in schools.
But some things haven't changed. "It's the great mystery of our time," announces Diana (Lindsay Duncan) sophisticated and possibly hung-over wife of Tory MP Robin Hesketh (Alex Jennings), as she prowls the space in her dressing gown. "The insatiable desire of the people of this country to be f**ked by an Old Etonian."
It gets a big laugh. But the play is less comfortable and more unsettling than its rather good jokes about politics. As the vaguely left-leaning Diana and the Thatcher-loving Robin circle one another, walking what is left of their wits, as Albee's Martha and George might have it, slugging it out along what are clearly well-worn channels, the story that emerges is more complex and more troubling than it first appears.
Directed by Simon Godwin, with a sensitivity and care that tries to minimise the problems of the wide Lyttleton stage, this portrait of a marriage is also a plea for humanity and understanding in public and private life, gently making the important point that playing to anyone's worst instincts and closing down opportunities for compassion is never a way a society or a family should proceed.
Woods writes with clarity and ease; as a former actor, he gives actors lines you can imagine they relish and he's good at landing jokes that betray a particular type of sardonic ennui. "My God, she's still alive!" Robin exclaims as he arrives home for the weekend. "I know! It's a nightmare," she replies, horrified. Structurally, though, his inexperience shows. There's a dip three-quarters of the way into the 90-minute running time, and when the revelation arrives that gives the play its profound emotional punch, he doesn't allow himself quite enough time to explore it. It's slightly odd that having lavished such love on the production, the National didn't manage to help him to solve this.
Nevertheless, it is a promising and engrossing debut – and one where the performances simply take the breath away. Duncan is just perfect as the wounded wife, disguising her hurt beneath a brittle glamour and a need to hurt – "All those headscarves I wore. The twin sets. The casual racism". The shades of boredom and anger that pass across her face as she listens to her husband are subtly varied; but there's love there too. The long pause after the moment when he says "I might still love you" speaks volumes.
As Robin, Jennings gets a lot of the best lines, and some of the best arguments; he is no cardboard Tory, set up to be hated. But what's extraordinary is the depth of feeling he finds and conveys. At the close, as the terrible, sad, secret at the heart of this dysfunctional relationship is revealed, his face just crumbles, frozen in grief and unhappiness, absolutely breaking your heart.