An old controversy has arisen over pornography; not the usual ruck about whether it is harmful to women, but a debate over the viewing of women being abused during the making of it.

This Monday UK Feminista is screening the documentary Hardcore, which offers a horrifying glimpse into the industry.

First screened on Channel 4 in 2001, it follows Felicity, a 25-year-old single mother living in the UK, who is desperate to make money to improve her daughter's opportunities. She is invited by a porn agent to meet movers and shakers in the so-called US 'adult industry'. The audience watches as she goes from a bright, sparky, pretty woman to a cynical and emotionally exhausted shell.

Her agent introduces her to performer Max Hardcore, notorious for abusing and humiliating women during filming. Aware of his reputation for choking women during oral sex – and that he often asks his co-stars to wear little girls' clothes – Felicity did not want to meet him, let alone work with him, yet she is pressured by her agent until she agrees.

When Hardcore chokes her she breaks down in tears, but he insists on her continuing, calling her a "fucking loser" and she is almost persuaded to continue until the documentary crew steps in for fear of being complicit in her rape.

Feminist group Scottish Women against Pornography says it should never be screened, saying it is a "filmed rape of Felicity" which will be "endlessly re-enacted long after she is gone". But in the early 1980s, Women Against Violence Against Women compiled a "slide show" of pornographic images, and activists, including myself, gave presentations to anti-pornography women's groups. The images ranged from Playboy centrefolds to a Hustler image of a woman being fed headfirst into a meat grinder, and a cartoon of a learning disabled child being penetrated by a penis in one of her ears with the semen shooting out of the other.

Undoubtedly, a number of those at the meetings were upset but the knowledge gleaned was an essential tool with which to fight the liberals when they argue that porn is "just pictures of people having sex". Other human rights campaigners rely on disturbing imagery to add strength to their arguments: footage of animals being caged and tortured; images of men being lynched in the American south by the Ku Klux Klan; pictures of mass graves in conflict zones.

UK Feminista acknowledges the film makes difficult viewing, but says it depicts the true face of the oft-glamorised porn industry. And importantly Felicity, who left the porn industry after the documentary, did consent to the film being shown.

We need to know the truth about the porn industry to be able to effectively campaign against it. Hardcore tells the truth. Watch it.

Hardcore will be screened in London on 18 July, at 6.30pm. See ukfeminista.org.uk