Considering how very small the UK is in the grand scheme of things, the mark left by our British film industry around the world is pretty impressive. After all, we have a number of sub-genres that are solely connected to our culture: Ealing, Carry On and Bond to name just a few.

But there's one that stands out in terms of being acutely aware of the social, cultural and political climate within a specific time, mostly covering the decade of the sixties, and that's the Kitchen sink drama. And one of the best examples of its time is now celebrating its 50th anniversary – Billy Liar.

There's nothing wrong with dreaming of having a better life, but Billy Fisher (Tom Courtenay) takes it a little too far. His day job is working in a funeral parlour in his home town of Bradford.

Billy has two problems, the first being he can't concentrate. He is so bored and disillusioned with the world around him that he often slips into daydreams, where he takes on many important guises within Ambrosia.

His second problem is that he has a real difficulty in telling the truth. Every sentence that comes out of his mouth is yet another strand on his growing web of lies. He even manages to be engaged to two very different women at the same time.

He tells everyone that he's off to London, to write scripts for the popular comedian Danny Boone (Leslie Randall), but this is news to Danny Boone himself, when he arrives in Bradford on a promotional visit.

Although Billy appears to be suffocating from a family and town that don't understand him, he doesn't help his cause with all the lies he tells.

And then his path once again crosses that of free spirit Liz (Julie Christie); if anyone can help him escape from his current mundane path, it's her.

I had a dream where you weren't allowed to smoke on trains. Weird eh?

According to the film's star, Courtenay got the role after taking over the part from Albert Finney in the stage production in London and impressing British director John Schlesinger, who offered him the lead in the film version.

His performance certainly solidified his reputation for being one of the brightest actors of his generation. But despite a truly mesmerising turn as Billy, the experience of making the film was enough to make Courtenay come to the conclusion that he was far more comfortable on stage, where he has stayed for the majority of his career.

Although Courtenay generally wins the plaudits, quite rightly, for his performance, it shouldn't take away from the script written by Keith Waterhouse, based on his novel. It is rich with imagination, as well as the internal dichotomy that Billy struggles with concerning his desire to succeed with an inability to leave the family nest. Surprisingly, Waterhouse also went on to write the TV series Worzel Gummidge later on in his career.

Compared to many of the other kitchen sink dramas of their day, Billy Liar is possibly one of the least dramatic due to its comic content. Billy is a likeable character, rich in humour, who is brimming with charm, despite his propensity for telling porky pies.

It may be fifty years old, but it's not just the fact this film has been nicely restored that makes it seem so fresh. Courtenay gives the kind of compelling performance that you rarely see anymore, and Schlesinger, who soon went Stateside to make his mark with films like Midnight Cowboy and Marathon Man, stays true to the rules of the kitchen sink, whilst squeezing out some originality all of his own.