Huddled around a smoking brazier early today , the fluorescent-vested union officials looked perfectly at home.

But surrounding them on the traffic island at the far end of Newport’s St Cross industrial estate, on the Isle of Wight, was a scene that looked a little different from the usual picket line. Battered army surplus boots stuck out of the handful of colourful tents, a half-drunk bottle of South African chardonnay lay on the grass, and the gazebo hastily bought from the local B&Q contained the expected tea, coffee and biscuits, but also two cartons of soya milk.

On a grass mound outside the HQ of wind turbine maker Vestas Wind Systems, which is set to shut down with the loss of up to 600 jobs, a new kind of industrial dispute has taken shape. About 25 workers have occupied the plant in an attempt to prevent the closure, scheduled for 31 July, supported by a unique “red and green” coalition.

This is a protest significant not just for the way in which it has seen environmental campaigners, socialist activists and trade unionists join forces, but also for the way in which members of a previously non-unionised workforce in the largely conservative island community have been mobilised in a way they never dreamed of.

Tonight, about 300 people marched from the town centre to the plant for a rally to show their support for the action. Inside, the men, who since their arrival on Monday have been sleeping shifts on office floors, take it in turns to go out on a balcony to wave at supporters or pass the time with a keyboard discovered under a desk. “People have been putting on headphones, playing prerecorded tracks and pretending to be DJs,” said Ian Terry, 23, one of the occupiers.

A game invented to kill time involves throwing and catching balls while seated on increasingly far apart office chairs in the corridor.

Since Thursday morning, Vestas’ management has been providing them with two meals a day, so far centred on cheese sandwiches but the men said they were still hungry. Tobacco has been provided by their workmates outside, who throw tennis balls stuffed with goodies.

Those that land short are scooped up using a pole of joined-together broom handles, with a sticky ball of tape attached.

Spirits are high, according to Terry. “The atmosphere is brilliant,” he said. “I think it’s amazing what people have done. We know there are different groups with different opinions on certain things but they’re all singing from the same hymn sheet and support is just snowballing.”

Outside Sean McDonagh, 32, a team leader at the plant, marvelled at the cultural shift of the last week. “For so long, management kept us down; they’ve broken us and bullied us,” he said. “To move up the ladder you had to do anything the management wanted. If you didn’t want to do that they didn’t want to know. People were too scared to stand up for themselves, because they were worried they’d lose their jobs. It’s good money, and that’s really what the management has worked on.”

All that has changed after the arrival, last month, of a handful of socialist environmental campaigners from the group Workers’ Climate Action.

By night, they camped at a farm near Cowes and by day set about hanging around the gates of Vestas’ two plants at shift-change times, handing out leaflets. Initially, they were met with scepticism, but gradually a small number of workers began to be convinced that action could make a difference.

Last week an occupation committee formed and by Monday evening the men had taken their places inside the plant.

Vestas, the world’s biggest wind turbine maker, claimed tonight that “outsiders” were involved in the occupation of the closure-threatened factory but the real blame lay with “faceless nimbys” who opposed wind schemes in Britain, leading to them having to close the factory.

The Denmark-based company, which will go to court on Wednesday seeking a possession order to stop the occupation, also said that green activists should support the switch of manufacturing from the UK to America which was its main market, explaining that having to send the blades by ship across the Atlantic raised the carbon footprint of Vestas.

Peter Kruse, a spokesman for Vestas at its head office in Copenhagen, said the company had been surprised by the occupation and would do all it could to bring it to a peaceful end. He refused to say whether the company would change its mind but said that even with some government aid it “can’t make ends meet”.

Campaigners rejected the claims that anyone other than Vestas staff were involved in the sit-in and blamed the company for changing its mind, from an expansion of the plant to closure.

But Kruse said the company could not sustain a business at Newport because of the credit crunch, a weakening of the pound and a lack of political action. Later, the Vestas man said he recognised the government was doing “a lot for us”.

Back on the traffic island, Jonathan Neale, of the Campaign Against Climate Change, said the coalition gathered there was like nothing he had ever seen in Britain.

“I grew up in the southern US and I remember when the civil rights movement started. This feels like 1960.”