Protesters against the use of 4x4s in urban areas say they are targeting celebrity owners of off-road vehicles as part of an escalating campaign. Members of a group calling itself the Alliance Against Urban 4x4s have tracked down and posted notices on vehicles owned by the actors Felicity Kendal and Robert Lindsay, and Chris Eubank, the former boxer.

They are targeting other high-profile figures including David and Victoria Beckham, said to own a Hummer, one of the largest off-road vehicles (it is adapted from an American military vehicle).

The tactics have raised fears that British protesters are moving towards the militant strategies of American groups such as the Earth Liberation Front (ELF), which claims to already have members throughout Europe. ELF activists have set light to 4x4s and doused them in acid.

British demonstrators, who insist they are non-violent, say they plan to attach fake parking tickets to celebrities’ cars informing them their 4x4s are “dirty and dangerous” and saying it is “a criminal offence” to drive an SUV in the city.

“Posh and Becks are the ultimate target,” said Suzy Edwards, 34, an Alliance Against Urban 4x4s supporter and environmental consultant from London. “Most of the public are behind us.”

The alliance said it was scouring celebrity magazines for new targets in an attempt to shame well-known figures into driving smaller vehicles. High-profile 4x4 owners have included the models Kate Moss and Claudia Schiffer, the entrepreneur Sir Richard Branson and the footballer Wayne Rooney, who runs a 2½-ton Cadillac Escalade.

Jenny Jones, a Green party member of the London assembly and anti-4x4 campaigner, said urban SUVs should carry the same social stigma as a fur coat during the height of the anti-fur campaign in the mid-1990s. “Owning a 4x4 has become some sort of fashion statement,” says Jones. “In reality it is little more than a sophisticated killing machine.”

Ken Livingstone, the London mayor, has already threatened to raise the capital’s congestion charge for drivers of off-road vehicles — or, as he prefers to call them, “idiots”.

Critics of the protesters say they are publicity seekers fighting a class war against the better-off. They fear British groups could be infiltrated by violent protesters in a similar way to the animal rights movement.

American 4x4 campaign groups have already discussed the possibility of a US-style campaign in Britain. The Rev Jim Ball, who leads the What Would Jesus Drive? campaign, said his supporters were committed to peaceful tactics: “We want all motorists to think about the impact they are having on God’s creation,” said Ball. “Transport is a moral issue and we want them to think: ‘Is this something Jesus would want me to do?’.”

Last week British campaigners were involved in their biggest anti-4x4 demonstrations to date. The alliance targeted mothers on school runs in London, Manchester, Birmingham and Nottingham. Protesters said they had stepped up their crusade after industry figures revealed a record number of off-road vehicles were sold last year.

They claim SUVs are damaging the environment, consume excessive fuel and pose a greater danger to pedestrians and other drivers because of their high-fronted bodywork. The demonstrators are calling for increased congestion charges for 4x4s in cities, higher road tax for SUVs causing the most pollution and a ban on 4x4 advertising.

“Parents who drive their kids to school in urban 4x4s are being extremely irresponsible,” said Siân Berry, a spokeswoman for the alliance. “These vehicles are totally unsuitable for city streets, jamming up roads, threatening children’s safety and increasing pollution.”

In America, where SUVs accounted for 25% of all new vehicles sold last year, anti-4x4 feeling has provoked some protesters to adopt extreme methods of persuasion. Outlines of dead bodies have been painted on the driveways of car owners with the slogan “Another dead Iraqi for your SUV” — a reference to their view that America invaded Iraq for oil.

Nails and screws have been dumped behind cars. The FBI investigated the ELF and its website was shut down.

So far Britain’s anti-SUV lobby has engaged in little more than leafleting and barracking of drivers. Campaigners dressed as lollipop ladies and headmasters in Hampstead, north London, handed out fake reports on a busy school route on Tuesday morning telling 4x4 drivers they “could do better”.

However, with 4x4s enjoying a 12.8% sales growth in Britain in 2004, the feud between protesters and manufacturers is increasingly combative. Honda was the first car maker to hit back at the alliance’s calls for SUVs to carry a “health warning”, pointing out that “all 4x4s are not the same”. Last week Land Rover joined the backlash.

“The vast majority of Land Rover products are diesel powered, making them more fuel-efficient and reducing emissions,” said Mark Foster, the firm’s spokesman. “They may not be the Toyota Prius but they are by no means the most gas-guzzling cars.”

Research in the United States has shown that someone struck by a 4x4 is more than twice as likely to die as someone hit by a saloon car travelling at the same speed. A car driver is also four times more likely to be killed if hit from the side by a 4x4 than by a saloon, according to America’s Insurance Institute for Highway Safety.

In Britain the alliance quotes figures from Churchill Insurance that show 4x4s are 25% more likely to be involved in crashes than ordinary family cars, while Land Rover counters with another study — this time by Ford — which found that 4x4 drivers were 20% less likely to be involved in a collision.

Honda also points to research by the European New Car Assessment Programme which rates its CR-V as among the safest 10% of vehicles in pedestrian crash tests, according to its independent safety standards. Honda’s CR-V claims better miles per gallon and lower CO2 emissions than some smaller family saloons.