He’s been through a breakdown, a Prozac addiction and hours of therapy, but David Brent hasn’t changed a bit. The world, however, has. It’s a harder, meaner place, with less time to indulge an amiable idiot.

That’s the premise of Life on the Road, Ricky Gervais’s uneven, but not entirely unsuccessful spin-off of The Office. Written, directed and starring Gervais, it’s a rehash that neither develops the character nor betrays him. It simply assumes that we still share his weaknesses and therefore care about the fool.

And we do – just. Brent was always, at heart, a dreamer. A man who means well and acts stupidly. Life on the Road works largely as a reminder of Gervais’s skill with this character’s tics – the whinnying laugh, the lip bit too late, that drowning stare to camera as he realises what he’s just said. At its best it carries the tradition of the little man struggling against his own confines. At its worst – some weak gags about fat people, a couple of moments where Brent’s too stupid for his back story – it’s small, shabby and outdated.

It’s a few years after the filming of The Office and the world has turned on Brent. He now works as a sales rep for Lavichem, a cleaning products supplier that sells scourers, dish cloths and tampons (“One size fits all ... No ... it doesn’t actually”). At his former workplace Wernham Hogg, Brent was largely tolerated as a harmless nuisance, but this new office is full of Finchys: aggressive salespeople who openly bully him. There’s a pseudo-Gareth (Tom Bennett) and a sort-of Dawn (Mandeep Dhillon), but the majority of the Lavichem workforce is hostile; less tolerant of outcasts and misfits. There’s less room for Brent in a workplace where individuality is counterproductive. While he was boss he could afford to dick about. At Lavichem his “spark” – as one sympathetic character calls it – can’t just be ignored, it needs to be snuffed out.

Facebook Twitter Pinterest New office, same fool … Ricky Gervais and Mandeep Dhillon. Photograph: BBC Films/Planet Photos

In Brent’s mind, escape lies down the open road and a series of gigs with his band, Foregone Conclusion. The reality is, of course, crushingly different. The band are hired hands who hate him. The gigs are sparsely attended disasters. The open road is the M25, a near-complete loop. And he’s paying for the whole thing – the tour bus, the hotel rooms, the new Sergio Georgini jacket and the backstage bowls of licorice all-sorts – out of his own pocket.

Why can't Ricky Gervais leave David Brent alone? Read more

The scenario makes sense, but there’s something tired in the execution. As he’s done often before, Gervais uses the tour and – to some extent – the film (and the promotion around it) to channel his own dormant rock star ambitions. So there’s very long performances of Forgone Conclusion songs (Equality Street, Lady Gypsy, Native American) which, while funny, do hammer on. The music (“New romantic, but modern. A bit Bublé, a bit David Essex”) is horrible. The lyrics are almost exclusively about calling for compassion: for black people, indigenous people, gays and the disabled (“Help the awkward through the door”). It’s in terribly bad taste, but that’s Brent. By appealing for understanding, he’s really appealing for people to understand him.

Facebook Twitter Pinterest Mockumentary … Ricky Gervais, left, in The Office in 2001 – with the Wernham Hogg crowd including Martin Freeman, Mackenzie Crook and Lucy Davis. Photograph: Sportsphoto Ltd/Allstar

It’s clear from early on that this is a Ricky Gervais solo outing. The moderating influence of his Office co-creator Stephen Merchant (not involved - something about “schedules”) is missing, leaving a patchy comedy that lacks discipline. The mockumentary format, used so brilliantly in the original show, goes for a wander once the action gets going. We’re never sure when the fictional camera crew is in attendance. There’s a heavy reliance on talking heads to sway us in Brent’s favour, particularly from rapper Doc Brown, who reprises his Comic Relief turn as Dom, an aspiring MC who’s been sucked into Brent’s orbit. Dom, a decent guy who can see the desperation behind Brent’s bluster, is the film’s Tim. A nice bloke who basically wants the best for Brent, even if he’s often the butt of his assumptions about race. In one difficult, but pointed scene, a very drunk Brent insists Dom call him “my nigger”. Dom, appalled, acquiesces because the cameras are rolling. Again – all Brent wants is validation. To Brent – as adrift in his friendship with a black man as he is delighted by it – this is the ultimate acceptance.

All of this relies on the audience liking, or even loving, David Brent as much as they once did, on giving him as many chances as Gervais has. It’s a problem that’s acknowledged twice: once via a scene in which a local DJ doesn’t know who Brent is, but says he was on a show “like The Call Centre” (a genuine workplace documentary that aired years after The Office); the next in a scene where Foregone Conclusion are booked to play a student union’s Shite Night (“the shittest bits of culture of the last 20 years”). The threat of a younger audience not getting David Brent is real, as is the danger that those of us who were there the first time might tire of him. Brent’s no Partridge and Gervais isn’t Coogan. At the same time, you can’t just throw a situation at him as you could with, say, Edina and Patsy. Gervais and Merchant built this character too well.

There were braver things that Gervais could have done with the character. The bravest being leaving him where he was. The Office - two series, two Christmas specials - was finished near-perfectly. It’s a shame to see the joke reheated. Still, the world isn’t getting any cleverer. All of us – from the boss who signs off an email about redundancies with details of his holiday plans to the Hollywood star who says he has no problem playing gay because he’ll “stand with his arm around his best mate in a pub. Not a problem” – have our Brent moments. The character endures, however hard or mean the world gets.