MORE than half a million people opposed to a war against Iraq were flooding into London today for the UK's biggest ever peace protest.

Around 500 people travelled down from Bolton on coaches laid on by Bolton Stop The War Coalition and members of the town's Muslim community. Many others set off by train shortly after 7am from Trinity Street Railway Station although they were delayed slightly when a train broke down at Blackrod. Rail bosses had to scramble a new engine from Preston. The mood of the Bolton protesters was upbeat. They carried banners with slogans such as "Stop The War" and "No blood for oil".

Some wore t-shirts proclaiming, "Don't Attack Iraq". Others wrapped up warm with scarves and woolly hats.

Darren Whitehead, aged 34, from Heaton, said: "There has not been a debate in Parliament and I just feel we are being led into a war that nobody wants. I have never been in a demonstration before in my life but I got out of bed at 5.30am for this one because it's something I strongly believe in."

Beth McPhail, aged 24, from Ramsbottom, said: "I just wanted to do something. I have no idea what the real motivation behind this war is and that's the scary thing."

The Don't Attack Iraq demonstration was due to begin at 12.30pm.

Those travelling from the north assembled at Gower Street and headed down Shaftsbury Avenue while those from London and everywhere else assembled at Embankment and headed past Westminster and Trafalgar Square.

The two strands of the march were to unite at Piccadilly and continue to Hyde Park to listen to speakers including US civil rights campaigner Jesse Jackson, former Labour MP Tony Benn and Liberal Democrat leader Charles Kennedy.

Other high profile figures at the rally were expected to include popstar Damon Albarn, model Kate Moss, peace campaigner Bianca Jagger, politician Mo Mowlam, playwright Harold Pinter and London mayor Ken Livingstone.

The rally has been co-ordinated by the Stop the War Coalition which is predicting the broadest grassroots mobilisation in British history, dwarfing anti-Vietnam rallies of the 1960s and peace rallies in the 1980s

They believe it will surpass the 400,000-strong countryside march last year.

Malcolm Pittock, the Coalition's Bolton spokesman, said it was a chance for the public to "show Tony Blair what they really think about this war".

Concerns have been expressed in the Jewish community that the anti-war march has been linked to the "Freedom for Palestine" campaign but some Jewish and Arab protesters will be marching together.

Police said there were no indications that the mass mobilisation of people would lead to violence.

The London protest, due to climax with a mass peace rally in Hyde Park, will be mirrored by rallies across the globe in major cities including New York, San Francisco, Paris, Rome, Berlin, Amsterdam, Tokyo and Cairo.

New Zealand had one of the first protests. Environmental pressure group Greenpeace flew a plane over Aukland harbour where the Americas Cup began.

In New York, a protest was due to take place near the United Nations headquarters where UN chief weapons inspector Hans Blix gave his report yesterday.

More than a million people are expected in Rome and 150,000 turned out on the streets of Melbourne.