If the phrase “I’m not running”, or anything similar to it ever falls from a politician’s lips, we can usually safely assume that they will be doing just that, and they’re just waiting for the perfect moment to strike. In David Hare’s new play, we aren’t so certain that this is the case. It follows Dr Pauline Gibson (Sian Brooke); a former medical student turned activist turned independent MP, and her rise to popular British politics. We begin in Newcastle, 1998, where she and then-lover Jack Gould (Alex Hassell) are ending their relationship. We flit back and forth between past and present, and Pauline’s life is punctuated by key moments in her career and both romantic and familial relationships.

Initially an A&E doctor, Pauline becomes involved in politics after she successfully runs a campaign to save Corby hospital, a notion proposed by none other than her ex, Jack Gould, who has since risen through the Labour party in the traditional manner, compromising and coalescing when need be, and is now running for leadership. Stirred by grassroots support for her, Pauline begins to consider running too, despite the fact that she’s not even a member. She’s landed here entirely by accident, somehow defying Labour’s longstanding reluctance to elect a female leader. Hare’s play examines the difference between the two of them, between tradition vs. independence and man vs. woman. The way in which they approach the bench are vastly different; he, slick, quick and brazenly confident, she sensible, paced and contemplative. Both are desirable qualities to have in a leader, but only one can have the top spot.

Brooke is practical and self-assured as Pauline, and she has what Jack doesn’t, which is the moral high ground. A newbie to the world of politics, she is painted as naïve, as all who ask too many questions often are, but Brooke gives her a stoic resolve. Joshua McGuire provides steadfast emotional and logistical support as Sandy, and by his definition (“the people you can’t get rid of”) is the closest thing she has to family.

Alex Hassell is charming and slippery as Blair-esque Labour candidate Jack Gould, who’s so terrifically conceited he says things like “you’ve always wanted to fuck me, and if you can’t do it in bed, then you’ll do it in the chamber at the House of Commons.” He’s a perfectly crafted character, almost everything he says is offensive in some way but precisely none of it is surprising. The arrogance and self-importance he must possess to believe that an ex-girlfriend would dedicated her entire life to seeking revenge against him is symptomatic of a man of his standing, and while truly ridiculous, is quite amusing to watch.

The structure of the narrative allows Hare to dip in and out of moments of Pauline’s life, including a gut-wrenching scene in which Pauline is visiting her mother, a domestic abuse victim for years and now an alcoholic. Another is a discussion with a Westminster employee about being the child of immigrants. While well-written, I can’t see what they add to the overall plot and seem to be randomly included.

Against Ralph Myers’ futuristic set design, two walls of a cubed room meeting at a right angle, Gould and Gibson flesh out their differences outside and we see that they, like the walls, are two sides of the same thing, but in it for extraordinarily different reasons. With on-the-nose observations and wry musings that reflect today’s sorry state of post-Brexit affairs, Hare has, in his seventeenth play for the National Theatre, again captured the tensions of our time. I’m Not Running, while it strays a little here and there, asks the big questions of our political period.

I’m Not Running is playing at the Lyttleton Theatre until 31 January. Its final performance will be broadcast by National Theatre Live. For more information and tickets, click here.