The last time a new work by Heathcote Williams was performed on the Edinburgh Festival Fringe 20-odd years ago, his trilogy of ecologically minded epic poems that began with Whale Nation had become some of the hottest property in poetry.

Whale Nation, Autogedden and Falling For A Dolphin, alongside another volume, Sacred Elephant, were produced in a series of lavishly illustrated large-format editions, while their subject matter predated a mainstream concern for life on Earth then still regarded as marginal.

The books sold in bucket-loads, while the performances by Williams’s long-term collaborator Roy Hutchins packed out the Traverse Theatre and the Assembly Rooms. Since then there’s been an apparent silence by Williams, whose loathing of the attention fame brings with it had previously caused him to retreat from public view during the 1960s.

Then he was a key figure of London’s counter-culture, where he mixed with the underground cognoscenti in a private life as colourful as his creative one.

Now, however, Williams is back with Zanzibar Cats, an hour’s worth of new short works performed, by Hutchins with the same sense of righteous anger as before, albeit leavened with an array of classical references that match the scope of their 21st-century pop sensibilities.

For the first time in an age Williams is even talking about his work.

This despite his understandable suspicions of a press which might prefer to focus on his 1960s affair with supermodel Jean Shrimpton or, more recently, his relationship with his son Charlie, later adopted by Pink Floyd guitarist Dave Gilmour, and who was recently imprisoned following his role in a demonstration against student fees in December 2010. Even this week, it seems, the tabloid paparazzi have been lurking outside Williams’s Oxford door. Beyond such intrusions, it’s Zanzibar Cats that concerns Williams the most.

“They’re driven by events,” he says of the poems, a mix of the political and the intimate. “In the case of Roaring Slogans at Passing Trees, a friend of mine, Dave Lawton, told me the story of a friend of his hitching a lift with an ex-soldier who’d served in Iraq and Afghanistan, and who was determined to use up all the oil in the world since he’d decided oil was the cause of wars. So he’d rip off petrol stations one after the other by using false number plates. He went on a kind of inverted eco-rampage.

“An Angel You Know I wrote when my mother died. It’s not a religious poem in the strictest sense, but comes from my noticing that when you’ve been close to someone most of your life, nature is actually quite kind. It lets you down gently through your experiencing visual and auditory hallucinations. You see the person you’ve lost. You hear them. As I say, it’s as if nature is intervening to reduce the trauma, not giving you more than you can endure. A survival tactic. If everyone was destroyed by losing someone there’d be no-one left.”

Born in Cheshire and nominally educated at Eton, Williams, christened John Henley Jasper Heathcote-Williams, received what he considers his real education visiting Speakers Corner in Hyde Park from the age of 12. Williams collected money for a tattooed orator called Jacobus van Dyn, and watched in awe as anyone who spoke out against the royal family was arrested. It was here Williams developed his anti-establishment streak, and the seeds were sown for his first book.

The Speakers, published when Williams was still in his early twenties, was a piece of reportage taken from four of the more irrational Hyde Park set, including van Dyn. It was later put on stage by Max Stafford-Clark’s collectively run Joint Stock company.

Williams’s first play, The Local Stigmatic, was produced at Edinburgh’s Traverse Theatre in 1966 in a double-bill with Harold Pinter’s The Dwarfs. The Local Stigmatic has since been championed by Al Pacino, who made a rarely seen film of the piece, about two fame-obsessed men who stalk and attack a film star. AC/DC, a look at mental health, opened at the Royal Court in 1970, causing writer/director Charles Marowitz to deem it the first play of the 21st century. Other works followed, although Williams’s activity on the Notting Hill squatting scene and the Albion Free State, which led to a book of graffiti of the period, took precedence. Williams worked with Ken Campbell on the anarchic Remember The Dentist, and penned the explicit lyrics to Why D’Ya Do It? on Marianne Faithfull’s 1979 album, Broken English.

The link with Hutchins came about after they met at the Elephant Fayre music festival in 1981 through comedian and veteran of the same squatting scene as Williams, Tony Allen, and the pair’s collaboration gradually evolved.

“Heathcote was really ahead of his time, “says Hutchins. “I remember doing Autogedden at a conference in Glasgow School of Art about traffic. I opened the weekend, and the effect of the poem was extraordinary. No-one was talking about the effects of cars on the environment then, but experts came up and said all the things they wanted to talk about were contained in the poem. ”

While the trilogy was made into BBC films, with Autogedden being narrated by Jeremy Irons, Williams ducked out of view. In the long public silence that followed, Williams concentrated on painting, “a pretty silent activity”, and travelled.

In another contradiction for such a private person, Williams also carved something of a niche for himself as a big-screen character actor. Initially, this was in arthouse projects such as being perfectly cast as Prospero in Derek Jarman’s 1979 version of Shakespeare’s The Tempest. That followed early appearances opposite beat poet Allen Ginsberg in the four-minute Love Love Love, directed by composer Michael Nyman, and in the tellingly named Wet Dreams, taken from ideas hatched by the Traverse Theatre’s early champion, Jim Haynes.

In 1987, Williams played a psychiatrist encouraging Emily Lloyd to swear in Wish You Were Here, took small parts in an adaptation of Charles Dickens’s Little Dorrit and in People Show co-founder Mike Figgis’s Newcastle-based gangster flick Stormy Monday, as well as appearing in Sally Potter’s film of Orlando.

In the 1990s Williams played a servant in Figgis’s version of Miss Julie starring Peter Mullan, and even appeared in an episode of Friends. More recently he played another sex kitten’s psychiatrist, this time counselling Sharon Stone in Basic Instinct 2. Williams laughs long and loud at that one. It’s a sound that frequently punctuates his conversation, which retains a similar playfulness to his work, both with Zanzibar Cats and a host of even newer pieces that include a forthcoming book of science-based poems and longer-form works on a par with Whale Nation.

“Robert Anton Wilson , the author of The Illuminatus!, said if it doesn’t make you laugh, it’s not true,” Williams chuckles. “Children first learn by playing. And laughing. In fact, you learn much more when you’re happily absorbing something than when it’s being shoved down your throat. Plato believed we’re the playthings of God, and therefore the greatest act of devotion, as God’s playthings, can be seen as just having fun. Which is a great perspective on life. Did you know that the proverbially industrious ant only spends about 10% of its time working? Progress is a pyrrhic victory over nature, as Karl Kraus said.

“So what are we doing now, the Western world? Benefiting from the Industrial Revolution but reluctant to do the washing up. Anarcho-primitivism is now being preached as a solution. But more simply,” says Williams, quoting Billy MacGuinness, one of the original Hyde Park speakers, “do nothing, slowly.”

Zanzibar Cats, Gilded Balloon to August 29. Visit www.zanzibarcats.co.uk