It takes one of the most obscene scandals in 20th-century British politics and all but kills it off with its self-righteous stance, plodding script, mournful violins and clunky construction.

The sincerity of feeling is unmistakable. So's the flat-footedness of the writing.

Emily Watson, who always brings a special grace to the screen, gives a multilayered performance to the role of Margaret Humphreys, who not only puts her own family dynamic at risk but finds herself physically threatened.

The film is heartbreaking, enraging, and ultimately uplifting, thanks to Loach's economic direction and Rita Munro's focused screenplay. The magnitude of the insanity is sometimes hard to grasp.