'A lot of people saw themselves in Billy Casper. . .'

The star of Barry Hines's novel A Kestrel for a Knave and then the ground-breaking and often heartbreaking movie Kes, Casper was the thin, unloved boy who naturally sank to the bottom of every pile. . . but had hidden depths, if only anyone bothered to try to find them.

It's 37 years since Kes was released, but it's still an enduring portrait of English working class life which is as relevant today as it was in the late Sixties and early Seventies.

The man who was responsible for bringing the Yorkshire author's novel to the screen was Ken Loach, and at the Bradford Film Festival next week a unique event will take place which gathers together Loach, Hines and the cast and crew of the movie for the first time since it wrapped.

Loach, who turns 70 this year, still thinks very fondly of Kes: "It was one of those films that I was very happy with. It all came together and we had a great cast."

But why does Kes have such enduring appeal? Why is it still shown in school rooms, still vividly remembered by those who have seen it?

"Over the years a lot of people saw themselves in the position that Billy was in. They identified with him to some degree or recognised that people like Billy have something within them that others rarely recognise."

Billy's special talent was his rapport with the titular kestrel, a moving relationship between a wild force of nature and a boy starved of affection and considered beneath the notice of most of his peers and teachers.

Those who have fallen through society's net have long been a favourite topic of Loach during his 40-odd year film career. Another project he'll always be associated with is Cathy Come Home, the TV play which exposed the hitherto brushed-underthe-carpet problem of homelessness in Britain. It led to a national campaign to raise awareness of the topic.

It's 40 years since Cathy Come Home was first aired. Have things changed?

"No, " he says. "Nothing's changed.

Homelessness is worse now.

"Until such time as we have a government who operate a planned economy, we will have homelessness.

"Any changes that came from Cathy Come Home were cosmetic. We've had successive governments who refused to plan the economy to solve these problems, but allow the market to drive the economy. When the economy is market-based, some people will always be priced out of a home."

With the likes of Kes, Cathy Come Home, Up the Junction - which tackled abortion - Raining Stones, Riff Raff and Ladybird, Ladybird, Loach has been given the mantle of a socialrealist film-maker. "That gets right up my nose, " he laughs.

So getting across a message is less important than telling a story?

"The story that doesn't resonate, that doesn't say something about the way we live, isn't worth telling, " he says.

Which explains why he no longer works on the small screen. Despite the recent experiment to reintroduce plays to daytime TV, Loach does not feel that the medium has a place for serious drama in its schedules.

"All they want is happy plays for happy people. TV companies have done their best to destroy TV as a serious medium. The chase for ratings has meant that apart from the very occasional programme, there is very little there to engage the brain.

"All you get is soap operas, hospital dramas, police shows. It's all very formulaic. It's like junk TV."

It's surprising that Loach didn't decamp abroad like many British film makers have. Did Hollywood never beckon? "It was a possibility in the Seventies, but American films are pretty gross. . . largely horrendous."

Turning 70 this year does not mean Loach is going to hang up the clapperboard. He's just completed his latest movie The Wind That Shakes the Barley, set in the Irish war of independence in the Twenties. So what's his greatest achievement? "The next one, always the next one, " he says.

"Old film-makers don't retire, they just keep trundling on until the bad notices finally force them out."