If you want to change the world, you have to get your hands dirty

New documentary Grasp The Nettle shows how state inaction on climate change fosters direct action on society's margins

Activist from Kew Bridge 'Eco Village' and the Parliament Square 'Democracy Village' apprehended by police after a sit-down protest

Two years before the Occupy movement sprang forth in New York and London, a motley group of land rights activists occupied a piece of disused land in west London to create an alternative model of moneyless, sustainable living. Little did they know they were about to embark on an extraordinary journey, at once harrowing and inspiring, that would take them into the heart of Westminster.

Dean Puckett's new documentary, Grasp the Nettle, follows the bewildering and even amusing exploits of this group over a one year and three month period. The result is a powerful film which raises often unsettling questions - not just about the draconian trajectory of state policy, but about the potential pitfalls of activism.

"We are creating an ecovillage community in the heart of this urban environment so we can promote and project a new way of living."

So declares the unofficial leader, Simon, on the day his motley band squat on an abandoned field in the midst of suburban Kew Bridge. The land had languished for over 12 years, a dumping ground for the rubbish of passing pedestrians.

As Dean watches on with his camera, in the next few months the ecovillagers rapidly convert what had been an eyesore for locals into a thriving community hub, dedicated to living ecologically without money.

They are a diverse bunch - mostly young people who have just emerged out of education and, in the wake of the 2008 financial crash, are uncertain of their future as well as disillusioned with the status quo. The film demonstrates that today's eco-activists aren't just concerned about climate change and the environment, but are simultaneously worried about foreign policy and the 'War on Terror'.

One of them, Gareth, confesses that his opposition to the wars in Iraq and Afghanistan is his primary reason for being in the village - to avoid being part of a system which oppresses in many different ways. Another, known only as 'Friend', puts it this way:

"By digging up the past, and burning it in the present, we are burning the future: big time."

Grasp the Nettle (2013) Official Trailer

In an effort to learn more about the Kew Bridge Eco Village, Dean gives up his job and flat to move in, and ends up becoming part of the movement he wants to understand.

The film captures many moments of idyllic beauty, as the ecovillagers use the branches of hazel trees and recycled rubbish to build 'benders' - small, insulated homes; go "skipping" every few days to pick up food thrown away in supermarket bins; build a manually operated shower and compost toilet; create a local seed bank to facilitate local food growing; and help distribute sandwiches thrown away by central London cafes to the city's homeless.

The ecovillage quickly becomes more than a model of sustainable community living and a social hub - it also begins to attract people who already live on the margins of society: homeless people, the unemployed, alcoholics. Some of them are invited to stay - one, Ieaun, who describes losing his job a year earlier and sleeping rough, explains that he was welcomed to live in the village "to feel the power of the earth and of working together."

An exclusive clip from Grasp The Nettle (2013) of Kew Bridge eco villagers making 'benders'

Then David Shayler arrives. Yes - the former MI5 whistleblower. The years of being pressurised by the security services appears, however, to have taken its toll. Shayler claims to be the latest incarnation of Jesus and the Messiah and now goes by the name "Dolores Kane".

When another ecovillager, Can, questions David's behaviour as he attracts increasing media attention, worried that his presence will be spun to portray the project as a cult, Shayler says:

"Well look at it this way. If you're bothered by a tranny and not bothered by people getting white phosphorous dropped on them in Gaza, you've got a problem."

But Shayler is the least of their worries. It soon turns out that the site is owned by developers who are planning to build a tower block of flats there. The ecovillagers argue that the development is against the wishes of the local community - and several local residents who visit the ecovillage including families corroborate this.

Tensions spark as the ecovillagers grapple with how to deal with the increasing numbers of homeless alcoholics creating chaos while trying to stave off the fast-approaching prospect of eviction. The film takes another turn when several of the villagers begin protesting against the wars in Iraq and Afghanistan outside Downing Street, carrying banners reading "We respect the soldiers. We do not support the war" and "Soldiers, come home alive!"

Eventually, they connect with veteran antiwar activist Maria Gallastegui, who is camped permanently outside the House of Commons at Parliament Square with the late Brian Haw. A dozen odd Kew Bridge veterans move in with her to create a "Democracy Village", fusing their environmental campaigning directly with a defiant politics of peace.

But fault-lines emerge as we witness glimpses of a longstanding feud between Maria and Brian, intensified by a constant barrage of police harassment, and a steady influx of homeless people seeking sanctuary from hostels which they describe as unsafe due to routine violence. As such, the film ratchets up from showcasing the admirable ideals of living sustainably and communally, to illustrating the whirlwind of turmoil that results as these ideals are forced to confront not just with government and private power - but also with themselves.

By the time it reaches its riveting climax, the film forces us to reflect on what makes activism worth doing - and how the internal conflicts of social movements can often be their own undoing.

But more than that, the film left me with the disconcerting sense that these activists have a point. Is something deeply wrong with our conventional democracy, when it simply cannot tolerate grassroots efforts to create self-reliant alternatives - alternatives that oppose the state's and corporations' ill-conceived decisions to doom us all to environmental catastrophe?

"We don't have the freedom to live as an ecological society", says Simon: "What's happening in the Democracy Village is a microcosm of the government's philosophy of solving problems by using force. We need to go beyond force and develop new ways of creating change."

Grasp The Nettle is being premiered at the Open CityDocs Fest in the Cinema Tent on Torrington Square, London WC1E, on Friday 21 June