Brussels and London are continuing attempts to thrash out a deal this week ahead of the December 31 deadline, but the two sides remain gridlocked on the issue of fishing quotas in UK waters once it leaves the 27-nation bloc.

“We hope that our EU friends will see sense and come to the table with something themselves,” the UK prime minister said during a visit to Greater Manchester on Friday.

“If that doesn’t happen, come January 1, we will be trading on WTO terms. Yes, it may be difficult at first, but this country will prosper mightily on any terms and under any arrangement.”

The PM’s words echo those of UK Chancellor Michael Gove, who, on Thursday, also said Britain would trade on WTO terms if it didn’t get a Brexit deal, meaning tariffs would be imposed on all UK imports from the EU.

It comes as European Commission Chief Negotiator Michel Barnier told the European Parliament on Friday that there were “just a few hours” left to complete the negotiations.

The European Parliament has set Barnier a deadline of Sunday by which to reach an agreement with his British counterparts, but Belgian MEP Guy Verhofstadt urged his fellow lawmakers “not to panic”.

He suggested the negotiations could continue beyond Sunday, adding, “If they [the UK] want us to eat their fish, well, we have to have the possibility to catch their fish in their waters."

Fishing makes up just 0.1 percent of the UK’s economy and a tiny portion of the EU’s, but it is still a major stumbling block in the Brexit talks, along with the ‘level playing field’ measures that ensure fair competition for businesses on both sides.

The EU and UK negotiators have sparred on issues of specific fishing-quota numbers, how often they should be negotiated and when they should take effect.

If the two sides do reach a deal, their respective parliaments will need to approve it, meaning that UK MPs, who have finished their duties for the festive break, could be called back every day until December 31 apart from Christmas Day.