The French government could tear up agreements which mean migrants are stopped before reaching British soil, it was warned today.

A cross-Channel deal means British immigration checks are carried out before people board trains or ferries in France.

Senior Tories say David Cameron has resisted the temptation to 'shout' at France over the crisis at Calais, because it risks moving the chaos to the Kent coast instead.

Scroll down for video

A cross-Channel deal means British immigration checks are carried out before people board trains or ferries in France

The French government could tear up agreements which mean migrants are stopped before reaching British soil, it was warned today

Senior French politicians have called for long-standing agreements to be town up so that the British border moves from Calais to Dover.

For more than 20 years, British immigration officials have been based at Coquelles in France while the French have a checkpoint at Cheriton in Kent.

It means vehicles boarding the Eurotunnel in France undergo both French exit checks and UK immigration checks.

So-called juxtaposed controls are also in place for boarding Eurostar services in Brussels, Paris and London St Pancras, as well as at ferry ports at Calais and Dunkirk.

Mr Cameron has repeatedly refused to 'point the finger of blame' at the French for the ongoing crisis at Coquelles, where hundreds of people have tried to illegally board train services to Britain.

Today he stressed that the cross-Channel deal was key to protecting the UK. He told ITV News the borders were 'secure, not least because our border controls are actually on the French side of the Channel'.

He added: 'We have the natural advantage of our sea border, we have redoubled that as it were by having border controls on the French side.'

The British government has taken the no-doubt sensible decision that just shouting at the French may not achieve anything Tory MP Damian Green

Former immigration minister Damian Green today said the UK government had resisted the temptation to criticise the French because they could tear up the agreement which means the border is on French soil.

He told MailOnline: 'In the end it's happening in France so the French have to be the effective authority.

'I think the British government has taken the no-doubt sensible decision that just shouting at the French may not achieve anything.

'The single biggest protection we have is our border is in France. If the French took that away we would be seeing those scenes in Kent - although the situation is terrible at the moment it could be much worse.'

The MP for Ashford added: 'The French appear to be getting the point that this can't carry on.

'They clearly have the capacity to protect the terminal if they have got the will to do so. Having said they are going to send more riot police in, we will know over the next couple of days whether they mean it or not.'

Former immigration minister Damian Green today said the UK government had resisted the temptation to criticise the French because they could tear up the agreement which means the border is on French soil

'TUNNEL MIGHT NEED TO BE SHUT' The Channel Tunnel might need to be closed permanently to stop migrants reaching Britain from Calais, Nigel Farage has suggested. The Ukip leader said 'it is always possible isn't it' when asked if closing the link between Britain and France, either temporarily or permanently, was a possible solution to the crisis. Mr Farage made the remark during a question and answer session following a speech on the European Union referendum and repeated the suggestion later with reporters. He said: 'It's always possible, isn't it. Let's say I hope it doesn't happen. 'It's important, the Channel Tunnel is important. It's important for trade, it's important for leisure. 'Let us hope those circumstances don't occur - but if the French authorities don't start to take a much stronger and tougher line it is a very real possibility.' Advertisement

British ministers are having to walk a diplomatic tightrope with the French, who they need to continue to allow Britain to carry out border checks on French soil.

Without the juxtaposed controls, immigration checks would not be made until someone reached Britain making it far easier for migrants to come and claim asylum.

Home Secretary Theresa May has defended using British taxpayers money to pay for a problem taking place on French soil. She said this week: 'We have juxtaposed controls at the border. We work together on dealing with this particular problem.'

However, there is growing pressure in France for the agreements to be scrapped with responsibility for immigration moved back to the UK coast.

Calais mayor Natacha Bouchart said: 'Calais is a hostage to the British. The UK border should be moved from Calais to the English side of the Channel because we're not here to do their jobs.'

Xavier Bertrand, a former French minister said: 'In Calais, it's a human drama which is taking place every day. Only a naval blockade at the Libyan coast could provide a solution.

'The UK has responsibility in this matter too. England allows these migrants to work without papers. The English border must be at Dover and not Calais.'

Former French minister Xavier Bertrand (left) and Calais mayor Natacha Bouchart (right) have both called for the border to be moved back to Britain from Calais

Labour's shadow home secretary Yvette Cooper said the Prime Minister's attempts at diplomacy with the French government 'isn't working'.

She added: 'Still not enough is being done to stop a difficult situation becoming desperate.

'We need far more action from the French Government to assess people arriving in France, to prevent people reaching Calais in the first place and to police the roads where lorries are targets.