Tens of thousands of illegal immigrants a year could land in Dover if the border controls at Calais are scrapped, the head of the UK Border Force union has warned.

British authorities would be powerless to return the hundreds of stowaways caught every day trying to sneak aboard ferries to Britain main’s ports from Calais if French politicians follow through with their threat to end the deal, Lucy Moreton added.

Migrant camps could also spring up along England’s south coast as migrants flock into the country, following the suspension of UK border controls in northern France, a Kent politician fears.

Calls from French presidential hopeful Alain Juppe for the border to be moved from northern France back to Britain have been met with alarm by border officials, MPs and local people in Dover

An estimated 7,000 people from Africa, Asia and the Middle East are currently living in a make-shift encampment on the edge of Calais hoping to start a new life in Britain

Last year UK Border guards foiled 30,629 attempts to cross to Britain illegally between April and July – an annual rate of 92,000, according to the latest Home Office figures

French presidential front runner Alain Juppe said it was ‘logical’ for checks to take place on UK soil now Britain is leaving the EU

The front-runner to become the next French president has called for Britain’s border checks in Calais to be scrapped.

Alain Juppe said it was ‘logical’ for checks to take place on UK soil now the country is leaving the EU.

The arrangements are underpinned by the Le Touquet agreement sealed between Britain and France in 2002 which dramatically cut illegal immigration across the channel.

Mrs Moreton, general secretary of the ISU union which represents officers from the UK Border Force, Immigration Service and HM Revenue and Customs, claims the end of the Le Touquet deal would mean the return to the illegal immigration chaos of the 2000s when the numbers seeking asylum reached a staggering 84,132 a year.

Last year UK Border guards foiled 30,629 attempts to cross to Britain illegally between April and July – an annual rate of 92,000, according to the latest Home Office figures.

Speaking to the MailOnline, Mrs Moreton said: ‘The scrapping of the Le Touquet agreement could mean the return of the large scale and chaotic illegal immigration to the UK from France that we saw in the 2000s.

‘Freight and passenger traffic would cross the channel before seeing UK Border authorities.

Pictures from June 2001 (above and below) show migrants gathering at the Sangatte Red Cross camp before trying to cross the channel to the UK - there are fears that the number of illegal immigrants entering the UK could soar if the border comes back to Britain

Lucy Moreton, general secretary of the ISU union, told the MailOnline today: ‘If the UK border were shifted back to the UK from northern France we would return to the situation pre-2002. Freight and passenger traffic would cross the channel before seeing UK Border authorities.'

Migrants try to secure safe passage to the UK in September 2001 before joint border controls were set up in Calais in 2002

French police search illegal immigrants found in a lorry at Calais bound for Dover in December 2000 before border controls were brought in under Le Touquet agreement. There are fears the UK authorities would buckle if border controls move back to Britain

‘This means that the hundreds of irregular migrants detected every day whilst still in France but attempting to reach the UK who are currently simply returned to the French authorities would have arrived in the UK and would have to be processed here.

‘Although applications for entry may be ultimately unsuccessful this can be a lengthy process putting strains on the detention estate; as well as pressures on the benefits and other support systems.’

Folkestone and Hythe MP Damian Collins warned the threat must be taken seriously but said Britain cannot accept ‘the illegal immigration of the past’.

He told MailOnline: ‘Alain Juppe is the front-runner in the French presidential elections so we have to take his threat to scrap the Le Touquet agreement seriously.

‘But we cannot allow the situation in Calais to occur in the UK.

‘People in Kent would not tolerate the arrival of large numbers of illegal immigrants. It would not be tolerated to see the situation of Calais-style migrant camps in the UK.’

Folkestone and Hythe MP Damian Collins warned the threat of the border returning to the UK must be taken seriously but said Britain cannot accept ‘the illegal immigration of the past’

Razor-wire fencing has been extended around the motorway leading to the Calais port as part of increased security measures to prevent migrants clambering on board trucks heading to the UK

Andrew Richardson, UKIP group leader of Dover District Council, said: ‘The scrapping of the Le Touquet agreement could well be carnage for Dover and Folkestone.'

Under the terms of Le Touquet agreement, no change to the location of the Anglo-French border could legally be made for two years

Last year UK Border guards foiled 30,629 attempts to cross to Britain illegally between April and July – an annual rate of 92,000, according to the latest Home Office figures

P&O Ferries say they are confident new measures will be put in place to prevent illegal immigrants over-running their services from Calais to Dover if UK border controls in France are scrapped

Hundreds of migrants walked between the sprawling jungle camp and the ferry port in Calais today as they planned their illegal route to the UK.

An estimated 7,000 from Africa, Asia and the Middle East are currently living in the make-shift encampment on the edge of town hoping to start a new life in Britain.

Razor-wire fencing has been extended around the motorway leading to the port as part of increased security measures to prevent migrants clambering on board trucks heading to the UK.

The hundreds of irregular migrants detected every day whilst still in France but attempting to reach the UK who are currently simply returned to the French authorities would have arrived in the UK and would have to be processed here.

A UKIP councillor claimed the scrapping of border controls in Calais would have a catastrophic effect on south of England.

Andrew Richardson, UKIP group leader of Dover District Council, said: ‘The scrapping of the Le Touquet agreement could well be carnage for Dover and Folkestone.

‘The French cannot simply open the flood gates and let the thousands of migrants waiting in Calais to walk through the Channel Tunnel.

‘This is a potentially catastrophic result of the Brexit vote.

‘The disruption [to cross-channel traffic] last summer by the migrants was disastrous for Dover and Folkestone.’

He added: ‘If a jungle-style migrant camp were to open in Dover UKIP would have to share some of the responsibility for it happening because we have called for Britain to leave the EU.

‘But the French have been calling for the scrapping of the Le Touquet agreement long before the Brexit vote. So this problem could have arisen whether we were in the EU or not.

‘The existence of a migrant camp on either side of the channel – in Calais or Dover – shows that we have failed to deal with this problem effectively.’

The idea that border controls return to the UK has been greeted by concern in Dover. Debbie Brooks (left) and Susan Fellows (right) said the influx of people would stretch border officials to breaking point

Glenn Morley (pictured with his family) said leaving the EU was a bad idea and had triggered the potential problem of the border being moved: ‘There would be thousands of people arriving on our shores and we won’t know who they are.'

Paul Cooper, 52, added: ‘It’s sad for the people that are in France and want to come to Britain but we can’t afford to look after everyone.’

Yesterday people in Dover told of their fears at the threat of large scale illegal immigration and migrant camps near their homes.

Susan Fellows, 72, said: ‘We don’t want all those people coming over from Calais. We can barely look after our own people, let alone look after everyone else.’

Debbie Brooks, legal secretary, 57, said: ‘Bringing the border controls back to Dover would not be good.

‘I think the Border Agency and HM Customs are stretched enough as it is, I don’t know how they would be able to cope.

‘Having a migrant camp in Dover would certainly put people off from coming to the area.

‘And if people are able to get across easily then it will encourage others to try to come illegally too.’

Paul Cooper, 52, unemployed said: ‘The UK border moving from Calais to Dover would be a bad thing.

‘It’s sad for the people that are in France and want to come to Britain but we can’t afford to look after everyone.’

Razor-wire fencing has been extended around the motorway leading to the Calais port as part of increased security measures to prevent migrants clambering on board trucks heading to the UK

Last week French President Francois Hollande said: 'Calling into question the Touquet deal on the pretext that Britain has voted for Brexit and will have to start negotiations to leave the Union doesn’t make sense.'

Glenn Morley, 45, a storeman, said: ‘I do not think coming out of the EU would be a good idea and this is one of the problems.

It’s sad for the people that are in France and want to come to Britain but we can’t afford to look after everyone.

‘There would be thousands of people arriving on our shores and we won’t know who they are.

‘They could well be refugees or migrants looking for a new life but they could also be terrorists and we won’t be able to keep them out.’

Today the Home Office tried to play down the threat of ending UK border controls at Calais but failed to offer a solution if the agreement was scrapped.

A Home Office spokeswoman said: ‘Last week French President Francois Hollande said: “Calling into question the Touquet deal on the pretext that Britain has voted for Brexit and will have to start negotiations to leave the Union doesn’t make sense.”

She added: ‘French Interior Minister Bernard Cazeneuve said: “The Touquet agreement, which allows the intervention of British forces in Calais, just as it allows French forces in Dover, is not being called into question following the exit of the UK from the European Union.”’

Under the terms of Le Touquet agreement, no change to the location of the Anglo-French border could legally be made for two years

P&O Ferries say they are confident new measures will be put in place to prevent illegal immigrants over-running their services from Calais to Dover if UK border controls in France are scrapped

Last year UK Border guards foiled 30,629 attempts to cross to Britain illegally between April and July – an annual rate of 92,000, according to the latest Home Office figures

P&O Ferries say they are confident new measures will be put in place to prevent illegal immigrants over-running their services from Calais to Dover if UK border controls in France are scrapped.

Spokesman Dan Bridgett told MailOnline: ‘Under the terms of Le Touquet agreement, no change to the location of the Anglo-French border could legally be made for two years.

‘Given that the French presidential election is not until May 2017, then in practical terms the earliest that current arrangements could be changed is May 2019 – three years away.