Theresa May is prepared to go to war over Gibraltar as Margaret Thatcher did over the Falklands, senior Tories claimed yesterday.
Former Conservative leader Lord Howard said the Prime Minister would show the same resolve in defending Gibraltar from Spain as her predecessor did in wresting the Falklands back from Argentina following the 1982 invasion, the Daily Mail reported.
And Defence Secretary Sir Michael Fallon said the UK was prepared to go "all the way" to keep the Rock out of Spain's clutches.
The angry warnings follow the extraordinary bid by Madrid last week to use Brexit to ramp up its historic claim on Gibraltar.
May yesterday spoke to Gibraltar's leader Fabian Picardo to reassure him that she would never "enter into a process of sovereignty negotiations with which Gibraltar is not content".
Brexit Secretary David Davis will underline the message today during talks with his counterpart in Madrid, when he will say Gibraltar's status is non-negotiable. The EU stunned No 10 on Friday by backing Spain over Gibraltar.
European Council president Donald Tusk said Madrid would be given the power to block any new EU-UK trade deal from applying to Gibraltar, leading to fears that Spain could attempt to lay siege to the Rock after Britain leaves the EU.
Spain yesterday upped the ante by dropping its historic threat to block an independent Scotland from joining the EU - a move that is likely to encourage the SNP to hold a second referendum.
Lord Howard likened the threat to Gibraltar to the aggressive stance adopted by Argentina to the Falkland Islands in the run-up to the war in the South Atlantic.
He added: "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."
His intervention provoked an angry response from the Left.
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."
Liberal Democrat leader Tim Farron described his intervention as "ludicrous", adding: "It is unbelievable that within a week of triggering Article 50 there are Conservatives already discussing potential wars with our European neighbours."
Former deputy prime minister Nick Clegg revealed that he vetoed the appointment of Lord Howard as the UK's commissioner to the EU, adding: "Looks like we all had a lucky escape." But the Defence Secretary suggested that the UK's commitment to Gibraltar was unshakeable.
Asked if the UK would support Gibraltar in the same way it had the Falklands, Sir Michael told the BBC's Andrew Marr Show: "We are going to look after Gibraltar - it is going to be protected all the way because the sovereignty of Gibraltar cannot be changed without the people of Gibraltar.
"They have been very clear they do not want to live under Spanish rule.' While few expect Britain to go to war with Spain, which is a fellow Nato ally, the bellicose response underlines the anger in Tory ranks at the attempt by Madrid to exploit Brexit.
Sources in Gibraltar have claimed the 30,000 fiercely patriotic residents of the Rock had been "betrayed" by Downing Street after May failed to mention their plight in her letter to Tusk formally notifying him of Britain's intention to leave the EU.
Government sources flatly denied claims the omission had been made at the request of Madrid. And Sir Michael pointed out that the special status of Gibraltar was mentioned eight times in the Government's white paper, which was cited by May in her letter.
Picardo yesterday said he was "not thrilled" by the situation but May had been "very supportive".
He added: "When we get the deal on Brexit, it must be a deal that applies across the United Kingdom in respect of future trade and if there is such a deal it is only fair, proper and right that it should also apply to Gibraltar."
A Downing Street spokesman said May used the call to Mr Picardo to "reiterate our long-standing position that the UK remains steadfastly committed to our support for Gibraltar, its people and its economy".
In a statement after the talks, Number 10 said: "The Prime Minister said we will never enter into arrangements under which the people of Gibraltar would pass under the sovereignty of another state against their freely and democratically expressed wishes, nor will we ever enter into a process of sovereignty negotiations with which Gibraltar is not content."
Rear Admiral Chris Parry, a former director of operational capability at the Ministry of Defence, warned that the Royal Navy was much smaller than during the Falklands War, although he said it retained the capacity to "cripple" Spain.