‘No way, Jose!’ Gibraltar will ‘never give up a single inch of the Rock’ to Spain

Mr Picardo, who has been in office since 2011, said the MPs’ “anxiety” was unnecessary.

“I understand Parliament’s anxiety to know the terms and implications of any UK-EU agreement for Gibraltar that is reached,” he said. “They will be satisfied.”

He added: “I can assure all your readers that Lord Cameron and I are working in lock-step to secure the arrangements needed for the economy and wellbeing of Gibraltar and its surrounding region to flourish.

“Gibraltarians are the most dedicated and experienced guardians of Gibraltar’s British, British, British sovereignty.

“And to anyone who tries to take that from us, my response has already been declared to the United Nations – ‘No way, Jose!”

Sir Bill Cash, the chairman of the ESC, said in his letter to Mr Rutley that he and the other members were concerned that Lord Cameron was trading away sovereignty in return for business opportunities.

The letter added the MPs had “serious concerns regarding the conduct and progress of the UK Government’s negotiations with the European Union in respect of a trade and border deal for Gibraltar”.

The MPs said they were concerned about plans to move the Schengen border – the border at which the EU’s free movement rules operate – to the airport, allowing European Frontex border guards to deal with travellers from Britain or Gibraltar.

Sir Bill also expressed anger that the future of Gibraltar airport was being discussed as part of the negotiations, saying: “Any role for Spain in the management of the airport or change to its status, no matter how seemingly small or innocuous, must be ruled out.”