Macron's likely victory to become the next President of France could lead to a new cross-Channel migrant crisis

• Candidate has promised to rip up border controls between France and the UK 
• Le Touquet agreement allows British to operate border controls in French port
• A No10 spokesman said the shared border was in France’s best interest

Emmanuel Macron’s likely victory to become the next President of France could lead to a new migrant crisis in Calais after he promised to rip up border controls between France and the UK.

The independent candidate said the existing agreement should be renegotiated, potentially reawakening a new wave of illegal immigration to Britain.

The threat will cause significant concerns that the presidential frontrunner – who has branded Brexit a ‘crime’ – could make the UK bear the brunt of another migration crisis.

The so-called Le Touquet agreement allows British officials to operate border controls in the French port even when it leaves the EU.

But French officials have long blamed the deal for fuelling huge populations at the notorious Jungle camp in Calais, where thousands of migrants travelled in the hope of reaching Britain.

Mr Macron had previously promised to keep the agreement in place, and his u-turn sparked concern in Downing Street.

He said: ‘If there was a simple answer [to Calais’ migration crisis], it would have been found. I want to put the Touquet treaty back on the table and to renegotiate the agreement.’

His call for a fresh deal will be seen as a clear attempt to win support from his presidential rival Marine Le Pen, who has promised to close France’s borders.

Despite enjoying a sizeable lead in the polls, a recent slump has left Mr Macron cautious of being overtaken by the National Front leader before the second election round on Sunday.

A wave of jihadist attacks in recent years has prompted huge public concern about the passport-free Schengen zone that has allowed attackers to move between European countries.

While Mr Macron is a key supporter of the EU and has called for even closer integration with Brussels, he is aware that a soft stance on immigration could hand an advantage to his far-right rival.

The threat to scrap controls has been used by beleaguered president Francois Hollande and was also a key part of the ‘Project Fear’ strategy in the Remain campaign.

David Cameron even suggested that killing the agreement would lead to Jungle-style migrant shanty sites springing up in the south coast of England.

Macron’s desire to draw focus on the deal will also prove worrying after his previous assurances that it would remain untouched.

He first addressed the issue during the referendum campaign when he vowed to end the system of ‘juxtaposed’ controls that would allow the UK a border presence in France even after Brexit.

‘The day this relationship unravels, migrants will no longer be in Calais,’ he said.

But he backtracked during an election campaign visit to Downing Street in February.

He said: ‘I reaffirmed my willingness first to have a fair execution of the Le Touquet agreement and to see what we can improve.

‘We have to improve some issues - and to pursue a further co-operation in terms of defence.’

The frontrunner has already prompted concerns that he may press for a hard Brexit deal due to his pro-European leanings and previous wanring to lure jobs back to France.

While the 6,000 inhabitants of the Jungle camp were kicked out when it was demolished last year, hundreds of migrants have returned to the area prompting fears that a new site could emerge.

The presidential candidate yesterday said his priority was to prevent the number of unaccompanied children but he also called for a reduction in the time taken to process asylum claims in France.

He also proposed a deal that would allow refugees from countries such as Syria to make asylum claims before they have reached the EU, saying it is ‘inhumane’ to allow them to take ‘mad risks’.

But he dismissed ideas that his plans to kill the Touquet agreement were anything to do with the ‘caricatures of Miss Le Len’.

‘France is a country that recognises asylum,’ he said.

Le Touqyet agreement, which has been in place since 2003, also allows French border patrols to operate in the UK.

A Downing Street spokesman said: ‘We have always been very clear that protecting and enhancing the shared border between the UK and France at Calais is in both the UK and France’s best interests.’