Buried 50ft down in sodden red clay, Swampy plots Britain's biggest fight yet with the car

In a dark underground network of tunnels, Britain's most determined road protesters brace themselves for what could be the biggest and most vicious roads battle to date.

There are 20 like Swampy, 23, prepared to live almost permanently underground at Allercombe in readiness for when the bulldozers move in to start work on the proposed Exeter-Honiton road scheme in Devon.

They and more than 100 other protesters have spent two years digging in to thwart the pounds 65m road improvements, developing protest techniques which have earned the site the title "the university of action".

But at Exeter Crown Court yesterday, a district judge granted the Highways Agency, the construction consortium Connect and the engineering firm Balfour Beatty an order for possession of land at Allercombe , near Exeter, where the demonstrators have set up camp. Another two hearings tomorrow and Friday will seek orders for two other nearby protest sites at Trollheim and Fairmile.

Then battle will commence. The protesters, up to 150 already in attendance with more expected, are adamant they will not go quietly.

The most determined have constructed tunnels up to 50ft deep, some barely big enough to squeeze through, others leading to a cluster of living chambers, lit by candles and torches. They believe they could last days, maybe even weeks, under the soggy red Devon clay. They have significant stocks of food and, for luxury, a mattress for a bed.

Swampy's reasons are clear. "We are living in a car culture and I don't believe that building a new road will help that," he said. "Without this protest I don't think people would be aware that they are building a super- highway all the way through the country."

When the moment comes, he intends to attach himself to a defensive device dubbed a "lock-on". This is a giant concrete block with a tube into which he will plunge and lodge his arm. No contractor will be able to come near, he believes, because of the gas canister embedded in it. "If they hit it with machinery, the lock-on will explode," he said.

A construction source said the potential for trouble in Devon was significant. "They're training people for building defences and road protests from around the country. Their defences are extraordinary. Newbury was heavy, but I think Honiton will be worse."

Fears have been compounded by growing claims that the vetting procedures for road protest security staff are too lax. A guard blackballed for allegedly pulling a knife on a protester at the Batheaston, Avon, protest was yesterday reported to be in a management position on another site.

Roger Higman, senior transport campaigner for Friends of the Earth, said they have been training legal observers to help defuse any trouble at Honiton. "There's no doubt that the protesters are getting more professional, more experienced and it's getting more difficult for the Government to remove them," he said.

"We had a number of reports during Newbury of problems with screening procedures for security which is one of the reasons why the legal observers role is so important. You cannot rely on the Government-appointed security forces. They are not properly trained."

Mr Higman added: "This is another scheme that dates back to the early 1990s when the Government had plans to build all over Britain. It should be reviewed."