What's the motivation?

With plenty of red carpet and stars to glide along it, the 49th London film festival opens tonight with a gala screening of The Constant Gardener. Given that the film is already on general release around the world, and is only a few weeks away from cinemas across Britain, some critics have grumbled that the festival has something of a secondhand feel.

Indeed, many of the films going before audiences in the coming days - like Terry Gilliam's Brothers Grimm, Michael Haneke's Hidden and Palme d'Or winner L'Enfant - have already been seen by international critics at other festivals.

This, however, is unlikely to taint them in the eyes of the viewing public, few of whom will have made it to Cannes, Venice or Berlin this year. As Artistic director, Sandra Sandra Hebron told Screen International, "This is primarily a festival for our audience."

The critics may have seen it all before, but this is a festival for the people, and it's giving them what they want, an eclectic mix of the best films from around the world.

In terms of headline-grabbing gongs, there is nothing in the league of a Palme d'Or or Golden Bear on offer either. But the best first feature film could land itself a Sutherland trophy, won last year by Jonathan Caouette's Tarnation. All together there are six awards up for grabs, four of them aimed at up and coming film-makers, but none that really register on the international scene.

It is safe to say film-makers do not bring their work to London for the chance of getting their hands on something shiny. Nor is it critical acclaim which brings them. For most of the films here, the reviews that count have already been written.

But this is a big festival, which draws large audiences and plenty of attention. The Edinburgh International Film Festival may have the high ground when it comes to international credibility, with John Huston famously calling it "the only festival that's worth a damn" but London is the biggest British event, with an expected 116,000 people going to see 280 films across 13 venues. You don't get that at Cannes, where even the critics struggle to get into the screenings.

The festival does also have the advantage of being situated on the doorstep of the British film industry. It may not yet have really established itself as an industry occasion, but positioning itself at the centre of the domestic scene does seem to be the long term aim of organisers. To that end, this year sees significant involvement from Investment from Film London and the London Development Agency, among others.

Much of the investment has gone onto initiatives aimed at developing skills and encouraging new talent. This year sees the launch of Dare to be Digital, a weeklong series of talks and workshops which are intended to give new film-makers the chance to explore the possibilities of digital cinema.

Festival organisers are also hoping for an increase in the buying and selling which takes place at most major film festivals. Last year's Industry Screening event, saw 34 films looking for UK distribution, screened specifically for potential buyers. Seven of these went on to secure national distribution. Festival producer Helen De Witt has said she expects a 10% increase this year on the 147 registered buyers who came to London in 2004.

Organisers have been talking up the commercial potential of the London Film Festival, but are the people they really need to convince listening?

Andy Engles, co-owner of Artificial Eye, the company responsible for bringing films like the Three Colours trilogy to British audiences, is exactly the kind of person they would like to see doing business at the festival. Last year his company bought the rights to two films after they were showcased here: Whisky and soon-to-be-released French drama Innocence.

While praising the organisation of the London Film festival, he is not intending to get out his check book this year. His company are promoting films in London, but generally do their buying at Cannes, Venice and Berlin. He said, "London is traditionally a best of the other festivals...you get to see the films first elsewhere."

The London festival is not somewhere this distributor would yet think of doing his shopping: "However, it is acquiring a reputation for showcasing up and coming British cinema. It also has new foreign films, but small ones. Many are very beautiful, but a distributor will have his work cut out with them."

This year 39 films take part in the industry screening event at the Curzon cinema, Soho, and there are some interesting movies among the hopefuls. The Steven Soderbergh-produced Keane, for instance, is almost certain to find a distributor, although it would probably doesn't need London's help to do that, having already been released in the US.

British film Song of Songs comes to the festival without distribution after premiering at the Edinburgh International Film Festival. Shot on DV, it is a challenging story dealing with an illicit relationship in the shrouded world of Orthodox Judaism in North London. Not a movie with universal appeal, but it was warmly received in Edinburgh, and the festival may yet give it a useful fillip.

"Films like this rely on the festival circuit", according to Song of Songs producer Gayle Griffiths. The first showing in Edinburgh "validated the film", allowing it to be seen by the public as well as the critics. She is optimistic about finding a distributor at the London event, but sees it "as one part of a process" which also includes ongoing private screenings for buyers.

Industry screenings at the festival bring buyers and films together. Perhaps as important is the attention drawn to the film through the festival and its tireless marketing machine. A film that does well with audiences and critics here is also more likely to get the distributors excited.

For all that, London is still not seen as a major marketplace; the serious business gets done in more exotic surroundings. Cannes welcomed 40,000 industry workers earlier this year, while on average, less than 2,000 professionals attend the London event.

As a comprehensive showcase of the best of the forthcoming movies, the event is a triumph. Industry folk will need a few more reasons to abandon the Riviera for the Thames, but the groundwork is being laid.