THERESA May has laughed off talk of war with Spain over Gibraltar, and insisted the Brexit negotiations will be “jaw-jaw”.

On Sunday, in a surprise intervention into Brexit diplomacy, former Tory leader Michael Howard compared Spanish demands to have a say in EU negotiations over Gibraltar, with Argentina’s invasion of the Falklands in 1982.

Referring to Margaret Thatcher, Lord Howard said May would “show the same resolve” as her predecessor.

He 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 our current prime minister will show the same resolve in standing by the people of Gibraltar,”

Howard’s comments came after Michael Fallon had suggested Britain would be willing to “go all the way” to protect the 32,000 Gibraltarians who live in the British overseas territory at the southern end of the Iberian Peninsula.

The Spanish have called for Britain to calm down, suggesting that some of May’s Tory colleagues have lost their cool. Ahead of a meeting with Brexit Secretary David Davis, Spain’s foreign minister, Alfonso Dastis, said: “Someone in the UK is losing their cool and there’s no need for it.”

The Prime Minister, who flew to Jordan yesterday for the start of a trade mission to the Middle East, was asked directly by reporters travelling with her, if the UK would go to war with Spain.

May laughed and replied: “What we are doing with all European countries in the European Union is sitting down and talking to them. We are going to talk to them about the best possible deal for the United Kingdom and for those countries, Spain included. It’s definitely jaw-jaw.”

Earlier in the day, May’s spokesman had refused to condemn Howard’s comments, but did say there would be no “taskforce” sent to Spain.

The stooshie erupted after European council draft guidelines said “no agreement between the EU and the United Kingdom may apply to the territory of Gibraltar without agreement between the Kingdom of Spain and the United Kingdom.”

In her six-page letter to the EU triggering Article 50, the Prime Minister didn’t even mention Gibraltar, and the Government seemed to have been caught off guard by the weekend’s events.

SNP MP Kirsty Blackman tweeted: “I’m no modern trade expert, but I didn’t expect the stance ‘comply or we will kill your people’ to feature in the EU-UK negotiations.”

Gibraltar was reluctantly ceded to Britain in the 1713 Treaty of Utrecht, and the people who live there have twice voted overwhelmingly to remain a British dependency.

Between 1997 and 2002, the Labour government held talks with Spain on establishing temporary joint sovereignty. Ninety-nine per cent of Gibraltarians voted against being anything other than British.

Although Spain has long contested Britain’s presence Gibraltar, much of the recent ire has been over financial services, with the rock having a reputation as a tax haven and place for offshore banking.

Previously, companies incorporated there and doing business abroad paid no tax. However, Gibraltar’s government recently imposed a 10 per cent corporate tax across the board, whether beneficiaries are residents or not.

Dr Alex Marshall, from the Scottish Centre for War Studies at Glasgow University, says it is in these areas, rather than militarily, where there could be conflict between Britain and Spain.

“The actual bargaining cards here are in the hands of the EU,” Marshall said. “It’s hard to see a softer outcome without some major trade-offs and transactions taking place such as, for example, greater regulation of the financial services sector within Gibraltar itself, or some other halfway house,”

The academic said he didn’t think the Spanish would be taking Lord Howard’s comments too seriously: “My own opinion is that it reflects the delusions of the Conservative Party and is part and parcel of an attempted blackmail process.

Marshall added: “This is all an attempt to find cards and to find threats in face of what is a very weak hand indeed.”