The gritty traditions of British social realist drama are deftly combined with the dark violence of a gangland thriller in London To Brighton, an accomplished first feature from writer/director Paul Andrew Williams.

Distinguished by its sharp compositions, heartfelt performances and unexpected tenderness, it unfolds as a compelling tale in which the influence of Ken Loach is marbled with the brutality of Get Carter.

Critical interest in Williams as a new talent should help to build a profile for the film that will pay off in solid theatrical returns for UK distributor Vertigo, especially if they can reassure potential audiences that it is more Mona Lisa than Lock, Stock And Two Smoking Barrels in its aspirations. Internationally, it should help put Williams on the map.

A former actor and experienced pop promo director, Williams certainly knows how to grab attention. London To Brighton begins in the kind of breathless rush that instantly hooks the audience. It is 3.07am. A woman and a young girl burst into a public toilet. They are both clearly frightened for their lives. Kelly (Lorraine Stanley) is badly beaten around the face. Joanne (Georgia Groome) is barely more than a child. It is immediately evident that something awful has happened. Even as they prepare to catch a train to Brighton it is equally evident that the consequences may follow them to the grave.

Spare and tightly controlled, the film balances forward momentum with revealing flashbacks that build towards a satisfying if not entirely unexpected denouement. It works as a thriller, but is even better at delineating the relationship between Kelly and Joanne; a surrogate mother and daughter clinging to each other like orphans in the storm.

There's just a hint of John Cassavetes' Gloria in the bond between them and an echo of The Searchers in the final images. Joanne finds a protector whilst Kelly discovers someone who brings out her maternal instincts. The way the scenario develops is anything but sentimental; Kelly is a prostitute and has played her part in providing Joanne for the pleasure of an older client.

Despite the unsavoury world that has brought them together, there is still a plaintive quality to their relationship.

Lorraine Stanley is terrific as Kelly, making her a tough, resilient survivor who always seems more real and complex than the typical cliche of the tart with a heart. Williams reveals an assurance with both actors and characterisations throughout the film.

Thuggish pimp Derek (Johnny Harris) is both vile and vulnerable as he leads the hunt to find the two women, aware that his life depends on finding them. His tormentor Stuart has a vicious way with a blade but is also fair-minded and Sam Spruell plays him with a simmering menace that is reminiscent of Paul Bettany's star-making performance in Gangster No. 1.

Williams screenplay operates on the basis that characters are always much more interesting if we understand why they behave the way they do. Everyone here has their reasons and that elevates the film above a simple saga of gangland revenge.

The evocative compositions by Christopher Ross capturing the bleak sanctuary of Brighton beach or the danger of London after dark also raise the quality of a first feature that leaves its mark.