FRANCE has warned the UK that it will not be “blackmailed” into accepting a “bad” post-Brexit trade deal because of Boris Johnson’s December 31 deadline.

Ministers from the 27 remaining European Union members will meet in Brussels on Tuesday to agree the negotiating mandate for the talks on the UK’s future relationship with the bloc.

Downing Street insisted the deadline would remain so that “we restore our economic and political independence on January 1”.

In a sign that the EU is prepared to take a tough line, French Europe minister Amelie de Montchalin insisted that her country’s farmers, fishermen and businesses would not pay the price for a trade deal to be in place by the end of the year.

She said: “In this negotiation it must be understood by British businesses that we do not want a bad agreement – almost certainly, that we will sign up to no blackmail.”

The Prime Minister has ruled out extending the transition period beyond December 31, meaning the UK will do business with the EU on World Trade Organisation (WTO) terms on January 1 2021 unless an agreement with Brussels is in place.

Refusing to allow the UK to dictate the timetable, de Montchalin said: “It is not because that Boris Johnson wants a deal at all costs for December 31 that we will sign, under pressure, a bad deal.”

In a further indication that access to UK fishing grounds will be one of the main flashpoints in the talks, the French minister said: “The fishermen have the right to be protected, they know very well that if we sign a bad deal they will lose enormously.”

The Prime Minister’s official spokesman said: “The UK’s primary objective in the negotiations is to ensure that we restore our economic and political independence on January 1 2021.”