More than 3,000 banner waving demonstrators gathered in central London as part of a series of protests against possible military action in Iraq.

Set against a backdrop of Big Ben and the Houses of Parliament, a number of speakers competed with whistles and the beating of drums to megaphone their message that the UK should not go to war against Saddam Hussein.

We have come together to oppose this war - we have come together for peace

Jeremy Corbyn Labour MP

The London rally, organised by the Stop the War Coalition, followed a national day of action.

Protesters took part in cycle rides, marches, road blockades and university "teach-ins" across the country in an event arranged to coincide with Hallowe'en.

Organisers hoped the demonstration, which followed a march attended by more than 100,000 people in September, would give Tony Blair and US President George Bush "a fright".

'Killing the innocent'

From a soapbox in Parliament Square, Labour MP Jeremy Corbyn told protesters on Thursday that starting the war would demonstrate the two premiers' "supine indifference" to the injustice faced by many in the world.

He said attacking Iraq would be "to kill the poor, the weak and the innocent".

To cheers, he stressed: "We have come together to oppose this war - we have come together for peace."

Mrs Tennent teaches her pupils not to hit back

He said MPs should be allowed to vote on whether British troops should be involved in any conflict, and with that the protest moved on to Downing Street.

There was a heavy police presence as the demonstrators, some wearing witches hats and many carrying pumpkin lanterns, wove their way past Churchill's statue to join CND protesters already in place in Whitehall.

'No justification'

Teacher Rosie Tennent, from Canterbury, held a candle in a jar, and said: "America has no idea what it is doing.

"I tell my children at school, 'you should not hit back - there is always a way of working things out', but we have senior statesmen here telling the world: 'Just hit back'. It just doesn't make sense."

We want to give Tony Blair and George Bush the fright of their lives this Halloween

Andrew Murray Stop the War Coalition

Carrying a pumpkin lantern, Jean Blaylock, 30, a student from the School of Oriental and African Studies, said: "I don't think there is any justification for this war.

"We shouldn't be attacking Iraq. This is about pure politics."

Musician James Brennan, banged his hand drum, and argued: "It's not just about Iraq, it's about Zimbabwe's Mr Mugabwe and the trouble in Ireland."

Poppy appeal

A 20-year-old Italian student of anthropology and development, who did not want to be named, said: "English people are always very keen on remembering the poppy appeal and the people who died in war.

"It seems to me a contradiction that people in the government are wearing a poppy but they are contemplating war."

Tony Benn, an arch left-winger and anti-war campaigner, said attacking Iraq was about "imperial needs - oil and domination".

He said President Bush, by his actions and words, had "created more terrorists than anyone else in modern history".

"In a few weeks' time women in Baghdad will be widows and children will be orphans," he said.

"I can't think of a time when I was more fearful of a world war than I am now because of what is being done by Blair and Bush."

There was a heavy police presence at Westminster

Scotland Yard estimated around 1,500 demonstrators were involved in the rally. There were eight arrests for public order offences during the protest.

Earlier, protesters handed in a 75,000 signature petition at Downing Street.

In other parts of the country, there were a range of protests.

Hallowe'en warning

In Canterbury, Kent, there was a candle-lit procession to the cathedral, where protestors unveiled huge banners to drape over the side of the building.

Students in Liverpool held a teach-in at the university, with dockers in also expected to take part.

A peaceful protest was planned in Burnley at the Peace Gardens in the city centre.

Coalition chairman Andrew Murray said: "Tony Blair and George Bush were worried by the demonstration in September, but we want to give them the fright of their lives this Hallowe'en."