Four days after formally triggering Article 50, the Prime Minister has been forced to reiterate the UK’s “steadfast commitment” to Gibraltar, as senior figures in the Conservative caused embarrassment by suggesting the UK could go to war with Spain, as it had done with Argentina over the Falklands.

Yesterday morning, a cabinet minister and a former Tory leader both appeared on television to strongly suggest Theresa May would be prepared to go to war with Spain, a Nato ally, if it used the Brexit negotiations to seek to assert sovereignty over the UK territory, something which it has at no point indicated it would do.

Defence Secretary Michael Fallon told the BBC’s Andrew Marr Show, hosted this week by Eddie Mair, that the UK would go “all the way” to protect Gibraltar and its people’s right to remain part of the United Kingdom.

Minutes later, the former Conservative leader Michael Howard told Sky News: “Thirty-five years ago this week, another woman prime minister sent a taskforce halfway across the world to defend the freedom of another small group of British people against another Spanish-speaking country, and I’m absolutely certain that our current prime minister will show the same resolve in standing by the people of Gibraltar.”

Gibraltar’s First Minister Fabian Picardo had earlier told Mr Mair that the possibility of shared sovereignty with Spain would “strip of us who we are” before adding that “the United Kingdom goes to war over the principle of consent all around the world”.

A Downing Street spokesperson said Theresa May had spoken to Mr Picardo that morning, and said she would “never” allow Gibraltar to share sovereignty with Spain, for as long as Gibraltar’s people did not wish for that to be the case.

On Friday morning, European Council President Donald Tusk published his draft guidelines for the forthcoming negotiations with the EU, which said Spain would be given veto over any deal that would affect the status of Gibraltar, a tiny UK territory on the southern tip of the Spanish mainland. It has been interpreted to mean that a separate deal may have to be negotiated for Gibraltar, over trade but also potentially over freedom of movement, which could require a hard border around the territory.

Gibraltar was not specifically mentioned in Theresa May’s 2,200 word letter triggering Article 50, which was handed to Donald Tusk on Wednesday morning. Mr Picardo said he had had “strategic and tactical discussions” with Theresa May over the letter, heavily implying he had lobbied for Gibraltar to be included. He said it had been included ‘tangentially’ via, the letter’s reference to the Government’s Article 50 White Paper, which makes specific reference to Gibraltar.

Spain has made territorial claims over Gibraltar for more than 300 years, and is understood to have lobbied the European Council to have Gibraltar’s status specifically mentioned in the draft negotiation guidelines.

Gibraltar held a referendum on remaining part of the UK in 2002 and voted 99 per cent in favour, but in last year’s EU referendum it voted 97 per cent remain.

Mr Fallon told the BBC the UK Government would “look after Gibraltar” and that the continuation of its UK sovereignty was unquestionable.

He told the BBC: “We are going to look after Gibraltar. Gibraltar will be protected all the way. The sovereignty of Gibraltar cannot be changed without the agreement of the people of Gibraltar and they have made it very clear they do not want to live under Spanish rule.”

Mr Picardo described the prospect of the territory ending up under shared control as “awful.”

He said: “It would strip us of who we are. It would not be British if sovereignty should be shared with Spain.

“It would be awful. Our home would be handed over to a party that has no claim to title.

“Our day to day lives would not be the lives that would we live today. We would be living in somebody else’s land.”

Commenting on Michael Howard’s warning of a potential war with Spain over Gibraltar, Tim Farron, Leader of the Liberal Democrats, said: “It is unbelievable that within a week of triggering Article 50 there are Conservatives already discussing potential wars with our European neighbours.

“In only a few days the Conservative-right are turning long term allies into potential enemies. I hope this isn’t a sign of the Government’s approach to the long negotiations to come.

“Brexiteers have gone from cheering to sabre rattling for war in four days, it is absolutely ludicrous.”

Labour’s shadow Foreign Secretary Emily Thornberry said: “Inflammatory comments like those by Michael Howard will not help Britain get what it needs from these difficult Brexit negotiations.

“Sadly, it’s typical of the botched Tory approach which threatens a bad deal for Britain.

“Labour is clear that the sovereignty of Gibraltar must be protected and that the interests of British citizens in Gibraltar are safeguarded.”