Loach pitches in for low-paid cleaners" announced a recent newspaper headline, adding a quote from the film-maker: "This will be a long war with many battles."
It seems that Ken Loach is still fighting his endless fight. Which Side Are You On? marks the 40th anniversary of his remarkable career.
Anthony Hayward's book declares that it is "the first detailed portrait of the world's leading social-realist film-maker", and the biographer's obvious identification with the director is both a strength and a limitation.
The story of Loach's journey, from university acting, through pioneering BBC drama, to gritty feature films, is exhaustively, and occasionally exhaustingly, chronicled.
At times, the detailing of actors "discovered" and awards won - including the Golden Spike of Valladolid - reads more like a filmography than a biography. Sometimes, Hayward's admiration tilts towards celebration. But along the way, the book offers unexpected evidence of the ambiguities that underpin Loach's character and work.
Loach's early career seems to contain few hints of the committed socialist to come. There are stories of standing as a Young Conservative in school elections, of acting alongside Kenneth Williams and Dudley Moore, of playing Brer Fox, of directing Agatha Christie's Murder at the Vicarage , of wearing ties and carrying a furled umbrella.
But Loach is quoted as saying, "I was embarrassingly ambitious at Oxford", and the speed of his development when he was accepted on a BBC directors'
course in the early Sixties is striking. From Z Cars through to The Wednesday Play , Hayward provides a fascinating account of the burgeoning of a radical talent.
"Everything we did," Loach tells his biographer, "was about questioning the establishment view... We wanted to draw blood."
For me, just starting my own career in television, what I remember is the exhilarating liberation of Cathy Come Home and Up the Junction , when Loach and his indispensable producer Tony Garnett took TV drama out of the studios and on to the streets.
The progression to feature films in the late Sixties, with Poor Cow and Kes , confirmed the arrival of an important British director.
Repeatedly, Hayward's biography records how the making of those films demonstrated Loach's determination to do things his way.
"A puppet master", the actor Robert Carlyle calls Loach, and the director's favourite writer, Jim Allen, is quoted as saying "his innocence is lethal, he's got a steel spine going up his back".
The seeming mismatch between Loach's low-key persona - "gentle" and "courteous" recur in the comments of colleagues - and his ruthless determination to get what he wants, is a regular theme of the book.
Hayward spends some time on a scene in Kes, describing how Loach arranged for unsuspecting schoolboys to be caned so as to generate convincing tears.
Recalling one of their rare disagreements, Garnett says: "Frankly, I would have stopped it, because life is more important than art. I don't think it's worth upsetting a child." Hayward comments that "realism was everything for Loach" and reports how the boys went on strike for an extra ten shillings after the caning.
From the late 1960s to the end of the 1970s, Hayward tracks Loach's determination to make political drama that would challenge the established order. Even the titles of those plays - The Golden Vision, The Big Flame, The Rank and File - speak of a BBC (in the years before multi-channel ratings warfare) confident of its independence against lobbyists such as Mary Whitehouse and letter-writing politicians.
The book gives an account of Loach's bleak times during Thatcher's Eighties, when he struggled to get anything made during seven years of almost uninterrupted censorship.
Hayward seems particularly engaged with his investigation of how Loach's documentary about rank and file workers' betrayal by their union leaders, A Question of Leadership , became a victim of what he calls, with arguable hyperbole, "the most sinister case of censorship in British commercial television".
His exploration of what happened takes up more than the space given to Cathy Come Home and Kes . We are told how, facing "a big overdraft and four kids", Loach was compelled to make a McDonald's commercial. "I checked with Greenpeace," the film-maker says disarmingly.
After the story of Loach's censorship battles with "the ghost of Robert Maxwell", the account of his successful return to feature films in the past 15 years feels somewhat dutiful. But it seems nothing has been able to dent those commitments. Working in Hollywood, Loach has still refused to have his name on a studio parking space.
Leslie Woodhead is a freelance documentary maker currently working on a BBC documentary for the tenth anniversary of the 1995 Srebrenica massacre.
Which Side Are You On? Ken Loach and His Films
Author - Anthony Hayward
Publisher - Bloomsbury
Pages - 308
Price - £20.00
ISBN - 0 7475 7044 2