Anti-war MP George Galloway has warned the government of trouble if plans for a mass rally in London are blocked.

The Labour MP said Culture Secretary Tessa Jowell had told Stop the War Coalition that protesters could march through the capital on 15 February but would be banned from gathering in Hyde Park afterwards for a rally.

We are genuinely concerned about safety and we never have rallies of this kind, at this time of year William Weston Royal Parks

The Royal Parks said Ms Jowell had been operating on their advice and had had "absolutely nothing" to do with the final decision.

Chief executive William Weston said park use was barred at this time of the year due to concern for public safety and for the damage that could be caused to the grass.

Stop The War estimates more than half-a-million people will join the march.

Warning

Mr Galloway, MP for Glasgow Kelvin and a vehement critic of war in Iraq, said such a ban would amount to an "absolute crime" against civil liberties in Britain.

He said: "I would want to warn Mrs Jowell, she can either choose between half-a-million people at the rally or half-a-million people in a riot.

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"That is what will surely happen if we tell them that, thanks to the British government, they are not allowed to attend a meeting at the end of the march."

Mr Weston said the Royal Parks had vetoed the rally following discussions with the Metropolitan Police and Westminster Council.

Crush warning

The Department for Culture, Media and Sport had simply "accepted our recommendation", he said.

"The Royal Parks, with the local authorities and the police, have concerns that the safety risks caused by the numbers attending the event - and the timing - had not been addressed," Mr Weston told BBC Radio 4's Today programme.

"It's about numbers of people, the depth of winter, the dark poorly lit park at this time of year and also, of course, the heavy build up through the winter weather, muddy ground and the sheer volume of numbers.

"People can get crushed, people can break their legs - there are a lot of things that happen at this time of year and it would be very unwise of us to take such a risk.

"The decision to ban this rally is entirely down to the Royal Parks. The secretary of state had absolutely nothing to do with it at all.

"We are genuinely concerned about safety and we never have rallies of this kind, at this time of year."

'Democratic right'

But Lindsay Jerman, convenor of the Stop the War coalition, said she believed the reason for the ban was "political".

The group had a "democratic right" to demonstrate and will be holding a rally on 15 February, she said.

"Perhaps if we can't have a winter demonstration, we can't have a winter war if this is the argument that is seriously being put forward," she told Today.

Galloway: Park ban is an 'absolute crime'

The rally would not be a riot - it would be peaceful and end in daylight, she said.

"I don't think we are saying that there can be a riot, but if you don't have a way of addressing people's political concerns and very, very strong feelings over the war in this country then it is much, much harder to disperse a crowd," said Ms Jerman.

"We are going to pursue this issue with Tessa Jowell ... we will be holding a rally on the 15th."

The Department of Culture, Media and Sport said the Stop the War Coalition had been refused permission to stage a rally in Hyde Park for safety reasons and concern over the park itself.

Protesters would be allowed to rally elsewhere if they wanted to, a spokeswoman said.

"It would not matter who had applied, they would not have been given permission to do it."