The British territory’s border was not included in the trade deal struck between the UK and the EU on Christmas Eve but the issue is still subject to the same negotiating deadline. London and Madrid are trying to agree arrangements for how the border will work when the transition period ends on December 31 and freedom of movement rules no longer apply to the UK. A senior member of the UK negotiating team said that talks are ongoing. “We are continuing to negotiate in the best interests of the people of Gibraltar and that is ongoing,” he said.

“Unfortunately, if the EU choose to exclude Gibraltar from this mandate then there’s little we can do about that in the main EU/UK agreement.

“What we can do is conduct a separate negotiation on Gibraltar’s half to get a good agreement for Gibraltar and that’s what we’re doing.”

Thousands of people cross the border between Gibraltar and Spain everyday for work and there are fears that a failure to agree a deal will result in chaos.

Both sides want to preserve a frictionless border but the talks have proved difficult because of the long-running sovereignty dispute over Gibraltar between the UK and Spain.

The Foreign Office said the UK Government is “totally committed to protecting Gibraltar’s interests” and “that includes ensuring border fluidity”.

Negotiators also pointed out that the agreement secured with Brussels will see quotas currently retained by EU fisheries slowly handed back to the UK over five years.

Over the period the value of 25 percent of fish caught by EU boats will be returned to Britain.

After the five years, annual negotiations will take place to determine quotas.

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The group said: “When push came to shove, despite the legal, moral and political strength of our case, fishing was sacrificed for other national objectives.

“Lacking legal, moral, or political negotiating leverage on fish, the EU made the whole trade deal contingent on a UK surrender on fisheries.

“In the end-game, the Prime Minister made the call and caved in on fish, despite the rhetoric and assurances.”