SUICIDE is no laughing matter. Screenwriters Steve Lewis and Tony Owen evidently disagree, contriving this comedy of errors about a beleaguered London underground driver who can earn a sizeable compensation package if he can persuade someone to leap in front of his train.

Even the most skilled scribes would struggle to navigate the thorny and sensitive moral dilemmas at the heart of Three And Out, and regrettably, Lewis and Owen aren’t up to the Herculean task, clumsily melding a farcical opening 30 minutes with the heart-rending emotions of the resolutely downbeat finale.

It’s no wonder that Aslef, the union representing London Underground drivers, has strongly opposed the film and announced its intention to protest the premiere.

The sombre musings of the second hour proves strangely compelling, by virtue of a tour de force supporting performance from Imelda Staunton that is far better than the film deserves, but crass running gags continue to spoil the mood.

London underground driver Paul Callow (Mackenzie Crook) is shell-shocked when a passenger accidentally falls on the track in front of his train.

A few days later, a heart attack victim suffers the same fate and Paul is surprised to learn from colleagues Vic (Mark Benton) and Ash (Rashan Stone) about an unspoken rule: if a driver witnesses three accidental deaths within the space of one month, he is immediately compensated with 10 years’ salary.

The cogs of Paul’s febrile imaginative whirr into action and he hatches a daring plan to find someone willing to throw themselves under his train for the money.

Deeply depressed Tommy Cassidy (Colm Meaney), who attempts to leap to his death off Holborn Viaduct, seems to fit the bill and the suicidal man agrees to Paul’s plan on the proviso that they travel to Liverpool so that Tommy can bid farewell to his loved ones.

As friendship blossoms between the two men, Paul begins to question their macabre scheme but as Tommy reminds him, “a deal is a deal”.

Three And Out is populated with crazed characters like a cannibalistic French chef and a foul-mouthed mistress, who continually distract from the film’s half-hearted efforts to provoke debate.

Crooks is a vapid leading man, unable to find any emotional depth.

Comedy and tragedy are unruly bedfellows and first-time director Jonathan Gershfield is poorly equipped to strike the right tone.