There's a scene in Paul Kelly's new film, Lawrence of Belgravia, in which his subject is seen riding the London Underground.

Although the viewer never sees this mysterious character in plain sight, we're given tantalising glimpses of him in odd-angled close-ups as a Birmingham-accented voice-over earnestly relates how desperate he is to be famous. This voice belongs to the singularly-named Lawrence, who, for the last 30 years as the driving force behind Felt, Denim and Go-Kart Mozart, has created some of the greatest pop music you've never heard.

This weekend's screening of Lawrence of Belgravia as part of Monorail Film Club will feature a Q and A with Kelly and Lawrence led by Belle and Sebastian singer Stuart Murdoch. A long-time fan, Murdoch was referencing Lawrence's work as far back as B&S's debut album, Tigermilk. More recently, an instrumental tribute simply called Lawrence by hot American band Girls was released on uber-limited heart-shaped vinyl. The man christened Lawrence Hayward, it seems, might just have found his time.

"It's amazing," says Lawrence, who's just arrived back at his cooker-free 12th-floor North London flat with a cup of tea, "even though I thought people would be naming their bands after me years ago.

"But I'm a very patient person, and now it's happened it feels wonderful. I'm not being blasé, because to have people be inspired by you, just as I was inspired by Lou Reed and Tom Verlaine, it means a lot, but I expected all this to happen in 1985."

Lawrence announced Felt to the world in 1979 with Index, a no-fi minimalist dirge made single of the week in music paper Sounds. By the time their debut mini-album, Crumbling The Antiseptic Beauty, was released a year later, Felt sounded like a suburban English Velvet Underground fronted by a man courting his own mystique long before Morrissey or Madonna reduced their names to legendary stand-alone status.

With Brit-pop looming, Lawrence formed Denim as a Glam-rock bubblegum critique of the new rock orthodoxy. Lawrence pulled the plug on the project after a scheduled single, Summer Smash, was withdrawn following the death of Princess Diana. Lawrence's next vehicle, Go-Kart Mozart, took Denim's novelty rock somewhere between a post Johnny Rotten Sex Pistols and Black Lace.

By the time Kelly started shooting Lawrence of Belgravia eight years ago, Lawrence was homeless. The drug problems that ensued as he recorded the third Go-Kart Mozart album (as with the film, it's just finished) would have made for a pretty colourful warts and all portrait. But that wasn't the film Kelly wanted to make.

"I wanted to celebrate Lawrence and everything he's about," he says.

"So I just followed him around while he was trying to make the album, and sometimes he'd disappear for six months and the whole process would become quite fractured, but I wanted the film to be seen through his eyes." Being constantly followed around by a camera has indeed been something of a life-saver for Lawrence.

"It actually made my life feel legitimate," he says. "When you're a kid at school and you save a goal or something, or you're interviewing yourself in the bath, you think, god, this could be a film, and now, all these childhood dreams are actually happening."

Even after his recent hardships, Lawrence retains an unabashed air of ambition, integrity and optimism.

"It's easy to make a record and sell a few thousand copies, but I don't see the point. You have to aim for the top. I want to be the toppermost of the poppermost."

Despite such chirpy, irony-free assertions, Lawrence had a habit of courting disaster even before Summer Smash. Felt's 1985 single, Primitive Painters, produced by Robin Guthrie of the Cocteau Twins and featuring Cocteaus vocalist Liz Fraser, should have seen Felt cross over into the mainstream. As it was, the band put out Let The Snakes Crinkle Their Heads To Death, a 28-minute album of instrumentals.

Denim's 1991 slot on Jools Holland's Later programme should also have taken Lawrence into the charts. Given Later's catch-all take on rock's rich tapestry, however, having a mirror-shaded Lawrence mouthing off on a song called Middle of the Road about how he hated funk, soul, early Dylan and Aretha Franklin probably didn't do him any favours. Even if the music did sound like The Velvet Underground's Sister Ray by way of Chirpy Chirpy Cheep Cheep. Two decades later, the deadpan result remains part of a conscious attempt to create a back-story beyond the music.

"The pop world is one of illusion and artifice," Lawrence observes, part theoretician, part star-struck circus side-show, part would-be Svengali. "But it's no good just being Gary Kemp. You've got to say something interesting as well. That's not to say what's in the film is fake, because all of it's true, but you have to manage that back-story as well."

Given how much his cult status cache looks set to rise on the back of the film, if he really wants to be famous, couldn't Lawrence simply reform Felt?

"I want to look forward, not back," is his answer. "Fans don't know what they want, but they'll want what I give them. All these groups re-forming attracts a negative kind of attention. Just because the fans want to hear old songs doesn't mean they're going to buy the new record. But if you're not producing new stuff, that represents a sickness in the music industry, I wouldn't be able to walk onstage and sing Primitive Painters. I want to sing something new."

Even with Go-Kart Mozart's On The Hot Dog Streets album and the accompanying Mozart Mini-Mart EP due for a 2012 release, Lawrence is conscious that a change might be coming.

"It's been quite hard doing Go-Kart Mozart, because people want Felt, but if it doesn't take off then I'll do a new album of singer/songwriter material. There's a book of poems I want to put out as well. I wrote them when I had to sell my guitar when I was homeless, but I kept on writing. It'll take about 10 years for people to like Go-Kart Mozart. Maybe longer. It takes a lot longer for people to understand things these days."

The Monorail Film Club screens Lawrence of Belgravia at Glasgow Film Theatre, Sunday December 4th, 6.30pm, followed by a Q and A with Lawrence and Paul Kelly and hosted by Stuart Murdoch.