Robert Harris’s latest thriller is about a former British Labour prime minister, out of the job for a year or so and now accused of war crimes by the International Criminal Court. Adam Lang is a gifted communicator and a fine actor, but – as we are told on almost every page – there is little of substance to the man. Everyone agrees that he’s charming, though. He plays tennis a lot, addresses people with hideously trendy overfamiliarity and spends occasional summer holidays at the Caribbean mansion of a pop-star. His black-haired, spiky wife is ferociously intelligent and apparently extremely politically committed, but not many people like her. The couple have three kids. The ex-PM’s loyal and initially unquestioning chief of staff was a towering Scot who, while none too bright, had a certain mechanistic eye for detail. Lang, we discover, was at first adored by the public but later derided for his vapid, ectoplasmic character, his failure to deliver a radical programme and his sycophantic closeness to a right-wing American administration which led directly to a catastrophic war in Iraq and those consequent charges of war crimes. Oh, and there’s also a sacked, off-message former British foreign secretary, clever and sharp and full of both principle and personal vindictiveness.

Now, is it just me, or do some of these characters, these situations, ring a bell somewhere, and strike some sort of chord with you? There’s more, too. The book is called The Ghost – and the phantom in question could be the slippery, empty, former PM. Or it could be that loyal Scottish chief of staff who bites the dust on about page one. But more likely it refers to the narrator – Adam Lang’s ghostwriter, a guileless political ingénue contracted to ghost the former PM’s memoirs for an agreeably large sum of money and who is at first charmed by Lang and then, over a rather short period of time cloistered with his subject on a desolate and empty Martha’s Vineyard in winter, has his eyes prised open. Now, we can fit names to the other characters – Blair, Cherie, Campbell, Cook; but who is this ghostly ghostwriter, exactly?

Robert Harris was one of the first, if not the first, political journalist to perceive in Tony Blair the prospect of a certain potential, of a certain greatness. According to some, he was an “early cheer-leader” for Blair and the new Labour project. As sometimes happens, he perhaps became a little too close for comfort, reporting on the election from the Blair’s private plane; a confidante as much as a reporter. The two had a certain falling out over the sacking of Peter Mandelson, with which Harris strongly disapproved. But back in 2001 the writer Geoffrey Wheatcroft surmised that Harris could have trousered a lot of money as Blair’s “historiographer royal” – his ghostwriter, in a way – but, out of principle, he never did. He’s done it now, instead, through the medium of fiction. The real Ghost, then, is Robert Harris.

And what a jubilantly spiteful ghost he has proved to be. Blair is skewered, with magnificent rudeness, on page after page. “That was when I realised I had a fundamental problem with our former prime minister,” the ghostwriter confesses, midway through. “He was not a psychologically credible character. In the flesh, or on the screen playing the part of a statesman, he seemed to have a strong personality. But somehow, when one sat down to think about him, he vanished.” Adam Lang possesses no ideology, still less any affection for the party he once represented. Worse, he connived with the CIA in the (illegal) torture of Al-Qaeda suspects and pins his hopes on escaping via a technicality. And all the time, he existed as a hapless puppet manipulated by – whom? Was it the CIA? Or some ghastly US arms manufacturer? Or someone closer to home?

The Ghost by Robert Harris

The names are changed but Tony Blair is the clear target of Harris's latest novel, says Peter Millar

BACKGROUND

• Extract: The Ghost by Robert Harris

• A short extract from The Ghost by Robert Harris

• Only the togas have changed

• Summer reading for lawyers

• Harris points pen at a leader very like Blair

BACKGROUND

• Pompeii by Robert Harris

• Trapped between wife and mistress

This, then, is the plot of the ghost’s thriller. Who was it controlling our husk of a prime minister; who persuaded him that it was a good idea to serve American interests at the expense of our own and receive – as the waspish former foreign secretary points out – nothing whatsoever in return, ever? Harris handles it all with some elan and subtlety, if you’re a fan of the genre. The bleak, damp, winter woods of Massachusetts are beautifully evoked; this is, in more ways than one, a cold book, but none the worse for that. Adam Lang’s incredulity at being fingered as a war criminal is truly believable, his insistence that everything he did was from the noblest of motives is balanced and credible. And the twist – you can see it coming, sure enough – is truly thrilling. The entire plot serves to confirm what the peacenik conspiracy theorists believed all along, except in one crucial respect (which would give away the ending).

The ghostwriter himself, though, remains a shady and spectral character, a mere cipher for the action. Come on, Robert – don’t be so modest.

Buy THE GHOST by Robert Harris
Hutchinson £18.99 pp310

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