Where, I wonder, did David Hare find the raw material for his irritating but engrossing new play? What dodgy personage was the inspiration for the ultra-confident fundraiser and fixer who threatens to embarrass and imperil new Labour? Or for the Cabinet minister whose businessman husband is facing trial in a foreign court for his iffy deals? Or for the PM who espouses religion but actually sees Downing Street as a stepping-stone to big, worldly things, meaning loads of cash?

Well, my natural tact combines with my fear of libel to stop me suggesting whom Otto Fallon, Meredith Guest and Alec Beasley contrive accidentally-on-purpose to resemble. All I’ll say is that, though no time-frame is specified in the programme, the play would seem to be set early last year — or at least at a time when a party insider could say that there’s no reason why a government that runs so hugely successful an economy “shouldn’t be in power for ever”.

The speaker is Otto, the central target in a play in which Hare takes aim at new Labour’s supposed complacency, hypocrisy, love of pragmatism and lack of principle. As played by Stanley Townsend, he’s spivvish, foxy and unscrupulous enough to buy off a school with a new gym when it’s about to expel the Home Secretary’s teenage daughter, Jessica Raine’s Suzette, for drug-taking. But the girl has sex with a journalist — one whose proprietor, unsurprisingly in Hare’s corrupt world, is facing jail for fraud — and spills the beans to him. With this embittered, vengeful child and and a criminal husband creating twin scandals, life isn’t easy for Tamsin Greig’s Meredith or for a party starting to teeter in the polls.

Parts of the play, for instance Meredith’s grilling by Anthony Calf’s genial yet steely PM, seem to this political innocent to have some of the authenticity of Granville-Barker’s Waste. But parts don’t wash, especially those involving Nicola Walker as Suzette’s ex-teacher and, improbably, the wife of Otto’s latest aide-de-camp. Hare has always been inclined to idealise and sometimes sentimentalise intelligent, self-sacrificing women, but Walker’s Lori is too obviously the play’s beating heart.

She befriended Suzette at the good comprehensive from which Meredith stupidly dispatched the girl to a bad, expensive boarding school, and she understands and rescues her now. She talks wisely about everything from the nation’s undervalued children to the wars the government is waging. And when she says that observing contemporary politics is like watching a car-crash, she’s clearly speaking for her author.

Yet there’s sharpness and wit here and even a semblance of balance in what finally comes across as a pretty cynical attack on cynicism. Adam James’s journo may be an implausibly hostile creation, a joky sketchwriter turned statutory rapist turned investigative reporter, but at least he’s allowed to argue that a nosy, pushy press is better than no press. Greig’s tough but vulnerable Meredith comes across as deluded, a neglectful mother who repeats the drear mantra that she went into politics “in order make a difference”, and doesn’t seem to see that making a difference means hounding asylum-seekers; but at least she believes what she says, at least she stands by her awful husband. And that’s not so bad, is it?

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