Riot police massed around the entrance of the Channel Tunnel today following threats by protesters to storm it along with UK-bound illegal migrants.
Squadrons of elite officers joined gendarmes in the show of strength near Calais.
It followed the arrival of hundreds of anarchists in the port who have set up a camp aimed at helping migrants ‘tear down the borders’ to England.
More than 800 police are in the town, with another 1,200 on standby nearby.
An uneasy stand-off soon developed with the protesters as a ‘spotter’ helicopter circled the area and police patrols swamped the town.
‘There is a serious risk of public disorder and for this reason we have officers everywhere,’ said a police spokesman.
‘The entrance to the Channel Tunnel is a particularly vulnerable target and so we have increased out presence around it.
‘If any unauthorised person makes any attempt to get near it, then they will be arrested.’
In the camp itself, protesters began to arrive from all over Europe, including many from Britain.
All are from a group calling itself ‘No Borders’, which has pledged to ‘tear down the borders’ stopping migrants getting across the Channel.
As their tents and marquees were pitched, some of the 2000 odd migrants sleeping rough in the Calais area began to join them.
One, who said he was an Afghan called Ahmed, said: ‘The camp organisers have offered us food and drink, as well as a chance to get to England.
‘They are here to support us. The French authorities repress us, but we have friends who believe our cause is a just one.’
Local authorities in Calais have gained an official order preventing anyone buying or possessing anything which might be used as a weapon–including substances which can start fires or be used to make Molotov cocktails.
They said they had received email threats by protestors pledging to destroy wire fences and other security measures around the Channel Tunnel .
There have also been threats to burn ‘symbols of capitalism’ including local government offices, and even hotels run by prominent global chains.
Local prefect Pierre de Bosquet confirmed that 2,000 officers were ‘in the vicinity’ of the town, along with a squadron of mounted officers.
Mr De Bosquet said police intelligence had revealed plans for wide scale violence.
Last month Natacha Bouchart, the mayor of Calais , said the UK’s lax asylum system and benefits culture had ‘imposed’ thousands of illegal migrants on her town.
In a blistering attack in which she also called for millions in compensation, Mrs Bouchart said the UK was entirely to blame for the those who use the port as a staging point.
Mrs Bouchart, a member of President Nicolas Sarkozy’s ruling UMP Party, even called for border controls to be lifted to allow all migrants to flood across the Channel at the earliest opportunity.
Such views are heartily supported by the militants organising the ‘No Border’ demonstrations, which are set to run until Saturday, when their main demonstration will take place.