The deal that lets UK border authorities check passports in France will be up for discussion after the General Election, Theresa May has said.
The PM told reporters she expects the new government will sit down with incoming French President Emmanuel Macron to talk about the crucial agreement.
It allows Britain to check incoming travellers’ documents in Calais, while the French can do the same in Dover.
Mr Macron suggested last year that the 2003 deal could be scrapped, but has since said he is willing to “improve” it.
Mrs May said: “It works for the benefit of both the UK and France and obviously in the government that is elected after 8 June, we will be sitting down and talking to Monsieur Macron and others about how that system has worked both to the benefit of France, as well as for the benefit of the UK.”
The agreement – known as Le Touquet treaty after the place it was agreed – has been criticised in France for leaving it with huge numbers of migrants trying to get to Britain, many of whom were stranded at the ‘Jungle’ camp before it was dismantled in October 2016.
Opposition parties hit out at the prospect of changes to the deal, which if scrapped would mean UK authorities having to wait until Dover before they can question travellers and check who is entering the country.
The UK Border Force helped supervise migrants when the ‘Jungle’ was closed
Liberal Democrat foreign affairs spokesman Tom Brake said: “The Conservatives have repeatedly claimed that Brexit will have no impact on border agreements with France, but now the Prime Minister has admitted that they are up for negotiation.
“Changes to Le Touquet will mean an upheaval for people travelling across the Channel, risk making our country less secure, and are yet another consequence of the Conservative approach to Brexit.”
Labour MP Peter Kyle, a pro-EU campaigner, said: “They told us Brexit would lead to no change at all in the Calais border arrangements, when the Prime Minister herself admits they are up for renegotiation.
He said it was “the latest in a long line of broken promises from those who campaigned to leave the European Union”.
“The Government’s hard Brexit course is putting our economy and our border security at risk,” he added.