LONDON - A group of European politicians (MEPs) released a letter Saturday calling on Britain to remain a member of the single market.

Their intervention comes as the man who launched Britain's campaign to leave the European Union prepares to hold a face-to-face meeting Monday with the chief Brexit negotiator in Brussels, Michel Barnier.

Nigel Farage, who sits as an MEP, co-founded the United Kingdom Independence Party (UKIP) over 20 years ago with the aim of campaigning for Britain to quit the bloc.

The two men will meet on Monday at the European Commission headquarters after Farage requested a meeting. His call came after Barnier met a group of British pro-remain politicians from Westminster.

James McGrory, executive director of the pro-EU group, Open Britain, said: "Sending Nigel Farage to Brussels to sort out Brexit is like sending an arsonist to put out a house fire. He has no answers to the costs and complexity of Brexit, other than to blithely say we should walk away with no deal, which would be an unmitigated disaster for our economy and our country.

"As it becomes clear that the Brexit that he and other leading Leave campaigners sold to the public is not deliverable, what is required is honesty and realism, neither of which are Nigel Farage's forte."

Farage has responded by saying Barnier had been listening to people who want to stop or delay Brexit, while he would represent the 17.4 million people in Britain who voted in the June, 2016 referendum to leave by a 52-48 margin.

The intensity of the war of words between leavers and remainers is expected to become heated in the coming months as crucial negotiations on a future trade deal between Britain and the EU gather pace.

Prime Minister Theresa May has insisted Britain will leave the EU in March, 2019, and at the same time will leave the EU single market and the customs union.

The Guardian newspaper reported in London Saturday that Theresa May is being urged by 20 British cross-party MEPs to change course and seek full membership of the European single market and customs.

In their letter the MEPs, including Conservative, Labor, Greens and Liberal Democrats, claim the case for staying in the internal market has become stronger since the referendum. They warn that crashing out of the economic grouping would make Britain poorer and suggest that voters should still be given a chance to rethink altogether.

A British government spokesman told the Guardian: "We will be leaving the single market and the customs union, taking control of our borders and ending the jurisdiction of the ECJ (European Court of Justice)."