Jim Loach, son of legendary director Ken Loach, proves a chip off the old block with his feature-film debut Oranges and Sunshine.

Clearly as socially committed as dad, his film tells the true story of Nottingham social worker Margaret Humphreys (Emily Watson), who uncovered the forced deportation of children in care from the United Kingdom to Australia, a scandalous practice that went on for decades but was covered up by both countries.

Doggedly pursuing the truth, Humphreys goes to Australia and encounters dozens of the now-adult migrants – including Hugo Weaving’s fragile Jack and David Wenham’s swaggering self-made Len – and learns how instead of the promise of “oranges and sunshine” they instead faced years of mistreatment and abuse.

Loach relates all this soberly and straightforwardly. It’s a good move. The child deportees’ fate is shocking enough on its own and doesn’t require the filmmaker to whip up any additional hysteria. Admittedly, Rona Munro’s script is a bit earnest and plodding, but Watson’s blazing integrity as Humphreys ensures the story still leaves the viewer reeling in outrage.

On general release from 1st April.