How campaigners stormed the citadel of the 4X4

Workers at Land Rover's Solihull production plant were left choking on their early morning tea yesterday when 30 Greenpeace activists stormed the assembly line and began bolting themselves to half-built cars in a protest against "gas-guzzling" four-wheel drives.

The jump-suited environmentalists ran in at 7am, shortly before work was due to begin. "This is a warning to 4x4 manufacturers and drivers that things must change," said one protester, Mark Strutt, who then remained chained to a handbrake for seven hours.

There was little reaction from the workers. A man in his fifties said he rarely thought about the environmental impact of his work, "but I can understand why they're concerned". He added: "I hope we're off home soon."

Activists said that they would leave only when Land Rover agreed to produce more fuel-efficient cars. Assembly resumed mid- afternoon, however, when firemen cut the protesters machinery.

Fifteen were arrested on suspicion of aggravated trespass. Greenpeace estimates the cost of lost production at £4m.

The protest is the first to directly target a car manufacturer's production line, but opposition to four-wheel drives has become more vociferous, with the establishment of direct-action campaigners such as the Alliance Against Urban 4x4s.

Road transport is thought to account for almost a quarter of Britain's climate-changing emissions and Land Rover is a serious offender, Greenpeace says. The Range Rover V8 does about 12 miles to the gallon (4.3km/litre) in urban areas and emits 352g of the greenhouse gas carbon dioxide a kilometre. By this figure, a 10-mile, twice-daily school run would produce carbon dioxide equivalent to the weight of a Mini in one school term, the group says.

Greenpeace's UK director, Stephen Tindale, was one of the first protesters to be arrested yesterday. A former diplomat and special advisor to New Labour who helped to write the environment section in the party's 1997 manifesto, he has been scathing about the government's approach to climate issues.

Mr Tindale told The Independent the group felt it had to take such direct action because car manufacturers and the Government were ignoring climate change warnings. He said. "Companies like Land Rover are aggressively marketing 4x4s for urban fashion use. It's the type of irresponsibility that other people are paying for with their lives." He was referring to the World Health Organisation estimate 150,000 die each year from the effects of climate change.

Mr Tindale said the protest was intended to get Land Rover to improve fuel efficiency in its vehicles, to stop marketing them to an urban elite who had no intention of taking them off-road, and to make the Government realise that the only way to tackle greenhouse gases and meet its emissions targets was to "get to grips with the explosion of 4x4 use". Sales have doubled in the past decade to 180,000 last year.

Mark Foster, a spokes-man for Land Rover, denied that the company was a "climate criminal". Speaking to reporters outside the plant gates, he said: "We accept that the petrol Range Rover will do just over 12mpg in urban areas but the majority [65 per cent] of Range Rovers we sell are diesel and do 20mpg. Ford is doing what it can to reducing emissions. But any development requires a sustainable business.

"We are in a tough industry - you only have to look at Longbridge [the closure of Rover] to see that - and in a free society people have the right to choose what car to drive."