You want the truth like Tom Cruise wanted the truth in A Few Good Men? Well, here it is. As a concept, Ricky Gervais’s tale of a world where no-one is capable of uttering a lie is inspired. But as a comedy, it’s a supreme downer.

Pity, because few British comedians have worked so hard to be accepted stateside as the creator of The Office and Extras.

The American entertainment industry adores Gervais. Its stars form an orderly queue to be lampooned in Extras (they turn out for him here, too), and The Office is that rarity, a British comedy successfully remade for the US market. Gervais has even had a guest spot on The Simpsons, which is like winning an Emmy and the lottery combined.

His success is due in large part to taking comedy as seriously as the Americans do. That, though, is where he comes unstuck in his Hollywood debut as a writer-director.

In The Invention of Lying, he overdoses on seriousness, binges on gravitas and does himself a terrible injury while reaching for a higher meaning. There are jokes here, certainly, but they wouldn’t be out of place in a Bergman movie. Or on a gallows.

Gervais plays Mark Bellison, otherwise known to acquaintances as “a chubby little loser”. Mark makes his living writing lectures for the screen about real events from history. Since there’s no lying, there’s no fiction. Even the ad industry must abide by the rules. “Pepsi,” says an ad on a bus, “for when they don’t have Coke.” Clever, right?

It’s when the action switches to the brutally honest interactions between people that the film starts to go wrong. We first meet Mark as he’s about to go on a date with Anna (played by Jennifer Garner, an actress who always looks as though she’s about to sneeze). Anna is distinctly unimpressed with Mark and doesn’t hold back from sharing her feelings. Nor does she spare us the details of what she gets up to upstairs while he waits for her downstairs. Really didn’t wish to know that.

It’s the same deal next day at the office, where Mark’s smarmy colleague (played by Rob Lowe), and his spiteful PA (Tina “30 Rock/Saturday Night Live/Sarah Palin impersonator” Fey) shred what remains of his self-esteem.

Gervais is a master at what might be called the “squiggle”, where the audience squirms at the same time as they giggle. His is the comedy of embarrassment, taken to the limit.

But in The Office, and in Extras, the harsh stuff was balanced by outbreaks of tenderness. Here, you wait a long time for someone to take the top off the milk of human kindness. Even then it turns out to be slightly sour.

Something has to give, for the sake of the plot if nothing else. Desperate for cash, Mark tells the bank he has more in his account than is there and is amazed when they hand it over.

Once he’s tasted the forbidden fruit of fibbing, there’s no stopping him. Strangers, his bosses, Anna – all benefit from Mark’s little, and not so little, white lies. But it’s the yarn he spins to his mother about heaven that takes Mark from chubby loser to the prophet everyone wants to hear from.

There’s more than an echo of The Life of Brian in one of the film’s few funny scenes, in which Mark is being quizzed by a crowd of doubters about the “Man in the Sky” who talks exclusively to him. Groundhog Day and Bruce Almighty come to mind as well.

You get the impression, though, that what Gervais was really reaching for was Harvey, the tale of the invisible 6ft rabbit (Spielberg is reportedly on that case too, with a “reimagining” of Harvey in development).

Like Henry Koster’s comic masterpiece, Gervais’s picture demands the audience buy into the joke, hook, line and surreality. But in this instance we can tell where the joke is heading from early on, mostly because we’ve seen it done so often.

Gervais and co-director Matthew Robinson also tend to take the line of least resistance between scenes. You can’t just tell what the next move is going to be, you can see three or four scenes down the line.

The tone, in contrast, is all over the place. If you think the early pessimism is over the top, get a load of the truckloads of optimism that arrive around the two thirds mark so an acceptable ending can be found.

Gervais is growing, slowly, into the movie star he so wants to be. His Night at the Museum appearances have been grimace-and-bear-it stuff, but Ghost Town showed he could carry a picture.

The Invention of Lying finds him with a cracking idea but without the ability to make it work. The comedy sorcerer’s apprenticeship continues for a while yet.

The Invention of Lying (12A)

**

Dirs: Ricky Gervais, Matthew Robinson

With: Ricky Gervais, Jennifer Garner, Rob Lowe