Simon Gray is waging a generational – and very personal – war at the Haymarket and, if his campaign requires one to take sides, I’m afraid I’ll have to join the ranks of the opposition.

It’s younger playwrights who provoke one of Gray’s most indulgent rants – in the concluding, overly long, scene – with a thinly veiled swipe at the likes of Patrick Marber and his allegedly sex-obsessed Closer, in which a foursome continually swap loves and lusts.

Gray’s characters here – a threesome of two brothers and the woman they both desire (and have) – are no better in practice but presume to take the moral higher ground because they never overtly acknowledge the situation. This might be viewed as subtlety or discretion by some, but for me, it lies at the heart of the problem with the piece.

The play covers 27 years of sibling rivalry, jealousy, guilt, uncertain paternity, co-dependency and heartache – and yet, despite a promising opening, it never really addresses the issues nor the intricacies of the entangled relations head on. The meatiest action takes place off-stage in the intervening years, which makes several scenes expository in the extreme (in particular, the final one, in which we’re denied two of the main players in place of a now-grown, not-quite prodigal daughter posing repeated “So, dad, what happened then”-type questions). When emotions are exposed on-stage, they’re spoiled by lines of stilted dialogue, erudite poetry references, “darling” prefixes and suffixes for every pet name uttered, or gestures to the point of parody (not least some full-throttled keening).

All that said, Gray’s script and Peter Hall’s direction do manage to wring some admirable performances out of Jasper Britton, as the successful, eventually knighted Michael who writes “novels everybody will buy and nobody will read”, and Toby Stephens, as the younger, crippled, failed but much more handsome brother Japes of the title. In Stephens’ tour-de-force scene, he returns home as a shockingly gaunt, liver-distended alcoholic (much resembling his mother Maggie Smith in her street-dweller role last year in Alan Bennett’s The Lady in the Van). Britton’s triumph is more understated, gradually but effectively aging through the years as he does until he becomes an utterly convincing carbon copy of his dead, Garrick-lunching father.

John Gunter’s Hampstead front-room set is purposely bland, with whitewash splashed across the walls, just as it is across the lives of the family dwelling within them. A quite fitting backdrop, really, for an evening drained of colour.

Terri Paddock

But the following WOS reviewer disagreed….

The West End has not treated Simon Gray, one of its elder statesmen playwrights, kindly lately. Either by bad luck (Cell Mates shuttered early when star Stephen Fry famously walked out on it days into the run when he had a breakdown), bad writing (Life Support) or bad timing (The Late Middle Classes, which toured but failed to come into town because no theatre was available, with the proprietors of one infamously choosing the terrible musical Boyband instead), he's had a bad run. But with the first and last of those experiences, he has at least turned them into extraordinary diary-type books about the process of putting on the plays that are even more fascinating than the plays themselves.

However, his new play, Japes (and which Gray has declared may well be his last), finds him back at the top of his form; and if audiences stay away (as I fear they might), it won't be because he hasn't done his job, but rather this agonisingly well-drawn portrait of a family tragedy if far too uncomfortable and uncompromising to really enjoy watching.

Charting nearly three decades in a triangular relationship between two brothers and the woman one of them marries but both of them love, it describes with heartbreaking clarity the ravages of sibling rivalry and jealousy, and how two brothers - bonded by the early loss of their parents, who died in a car crash - are locked in the contradictory impulses of love and loathing.

Michael (Jasper Britton), turns into a successful novelist, while his younger brother Jason, known as Japes (Toby Stephens), desperately seeks to follow in his footsteps but succeeds only in becoming an unsuccessful academic in foreign parts, and finds refuge instead in drink.

Gray has suggested that the play is intensely autobiographical, since his own younger brother, who was an academic, died of his alcoholism a few years ago; and Gray has fought a long and hard battle with the bottle himself, so knows of what he writes.

The play is informed by remarkable insight and astonishingly bald, nakedly emotional honesty is showing its characters at the very edges of their existence: the scene that ends the first act - with an offensively drunk Japes drifting in and out of rage and reason, and his helpless brother howling in despair over his eventually unconscious body, is one of the most personal and moving in the West End at the moment.

Michael, meanwhile, has a no less shocking scene at the end of the second act, when his long-lost, disaffected daughter, returns home for a confrontation of her own.

Both Stephens and Britton give utterly remarkable performances, brilliantly charting the changes in their lives. Stephens plays drunk with amazing realism; and I have certainly never seen an actor age quite so convincingly as Britton, from youthful ambition to Garrick Club regular in the image of his character's father. And Clare Swinburne, as the woman between them, also gives a painfully well-observed portrait of a woman stuck with the repercussions of having made the wrong choice of brother to marry.

Peter Hall's fine production superbly catches the changing emotional colours of this highly charged landscape.

Mark Shenton