Eric Knight is remembered, if at all, as the author of the 1940 bestseller Lassie Come Home. Now almost a piece of folklore, it's a heartwarming tale of a handsome brown-and-white collie dog sold by its impoverished owner, a Yorkshire miner, to a local aristocrat, who takes her to northern Scotland, whence she makes a heroic return journey back to her 10-year-old master Joe. It was successfully filmed by MGM in 1943, and followed by half-a-dozen sequels and a long-running TV series.

Knight was in fact among the most interesting writers of his time. He was born into a Yorkshire working-class family in 1897, lost his father when he was three, and after some years as a child labourer he emigrated to the States at the age of 15, where he got himself an education in Boston, before returning to Europe with a Canadian infantry regiment in the Great War. After the war he took various jobs, finally turning to journalism, and he became a highly regarded film critic in Philadelphia before combining farming and fiction.

His attachment to literature and abiding love of the English countryside, his common-sense left-wing politics, as well as his appearance, invite comparison with Orwell. And after achieving some literary success he too died young, being killed in a plane crash in 1943 while serving as a major in the film-making section of the US army. Sadly, a collection of his eloquent letters to the British cineaste Paul Rotha, Portrait of a Flying Yorkshireman, is long out of print, but You Play the Black and the Red Comes Up, his brilliant pastiche hard-boiled pulp novel set in California and published in 1938, is available in paperback.

There's a lot of Knight in the character of little Joe Carraclough (sweetly played by Jonathan Mason), the lonely lad who adores the eponymous heroine of writer-director Charles Sturridge's Lassie. This attractive version of the novel is set very specifically in a bitterly divided 1938 Yorkshire. The pit where Joe's father works is about to close, the local upper classes are indifferent to the workers' fate, and the clouds of the approaching war become darker by the day. A good deal of time is spent establishing the social injustice that lies behind the need to sell Lassie, and her journey, when it comes, coincides with the outbreak of the Second World War. Following the original 1943 film quite closely, though shot in Scotland, Ireland and the Isle of Man instead of the west coast of America, it is a story of love, freedom, survival and homecoming, a kindly, sentimental canine road movie.

It is, however, somewhat flawed, partly through the decision to place it so precisely at the time it was written. What begins as a fairly tough story of social exploitation ends up as an unironic paean to the class system and the very exploitation of the working class that produced the need to sell Lassie in the first place. Peter O'Toole's haughtily dotty duke, who bought the dog and then connives in giving her back, becomes the movie's generous hero, in much the same way as an upper-class woman so patronisingly dominates another recent picture about the same period, Mrs Henderson Presents.

The villain of the piece is the duke's dogkeeper, who's been obediently doing his master's dirty work. The hopes for a future where a more just society will prevail are forgotten, which is a pity as Eric Knight's last completed work was the script for World of Plenty, a celebrated documentary on the creation of a more equitable postwar world.