Eco-protest 'to swamp London'

The campaigners will call on ministers to impose tough rules on carbon emissions by law.

The march will begin at Millbank and end at the American Embassy, where a series of talks will be given by leading green politicians, including Chris Huhne and Michael Meacher.

It is timed to coincide with the UN climate change talks taking place in Bali and parallel marches will be staged in 50 other countries.

Organisers say they hope up to 40,000 people could attend the rally.

"Last year we attracted 35,000 people and we hope this will be bigger," said Phil Thornhill of the Campaign Against Climate Change, which is organising the event.

"This is a problem that requires a global solution, so we are also targeting the US embassy, as America has been seen to be against many of the practical changes needed." The march will stop at Downing Street to deliver a petition to Prime Minister Gordon Brown.

Organisers say they are confident the protest will run smoothly.

"I hope we can bring central London to a standstill and we hope the police will have taken all of the necessary precautions - we know a lot of the roads in the area are being closed," said Mr Thornhill.

The group has also created a series of posters, downloadable from its website, which include a "wanted" poster featuring George Bush.

The demonstration will also be attended by dozens of smaller campaign groups, such as the Campaign for Eco-Vegetarianism. Seventy members of the student People & Planet group will attend as the culmination of a campaign to try to make universities and sixth forms more environmentally friendly.

"Seven universities will be there but students across the globe are taking action around the talks in Bali," said University College London student Richard Roaf.

"Students are more environmentally aware than ever - we know we will have to live with the effects of a damaged planet. We are inviting everyone who agrees to join us at the march on Saturday to send this message through the medium of song."