Emmanuel Macron, the French presidential favourite, says he will renegotiate France’s border agreement with the UK, raising the prospect of a “Jungle” refugee camp being set up in Kent.

Mr Macron, who will go head to head against Marine Le Pen in the final round of the election next month, said the Le Touquet treaty, under which British border guards operate in Calais, should be “back on the table”.

David Cameron warned last year that if the British border at the entrance to the Channel Tunnel in Calais was removed after Brexit, refugees would relocate to Britain.