Less than a week after Britain triggered the formal process of leaving the European Union
, London and Madrid were at loggerheads over Gibraltar, a British-controlled rocky headland on the southern tip of Spain.
The EU's draft negotiating document on Brexit, published on Friday, suggested that Gibraltar could only be part of any future trade deal if Spain gave its approval.
That prompted fury in Britain: On Sunday, Lord Michael Howard, a former leader of the governing Conservative Party, even suggested that the UK might go to war over the dispute.
Gibraltar -- a three-mile long headland with a population of 32,000 people -- is a British Overseas Territory whose residents remain fiercely loyal to Britain but whose sovereignty is claimed by Spain.
To the surprise of Downing Street, the territorial tangle made its way into the draft Brexit negotiating position published by European Council President Donald Tusk on Friday.
"After the United Kingdom leaves the Union, no agreement between the EU and the United Kingdom may apply to the territory of Gibraltar without the agreement between the Kingdom of Spain and the United Kingdom," the guidelines said.
In an interview on Sunday, Howard to urged a strong response, drawing a parallel with the Falkland Islands in the southern Atlantic, over which Britain and Argentina went to war for 10 weeks in 1982 under the government of Margaret Thatcher.
"I do think it is a remarkable coincidence that 35 years ago this week, that another woman Prime Minister sent a taskforce half way across the world to protect another small group of British people against another Spanish speaking country," Howard told Sky News.
Howard said May should "show the same resolve in looking after the interests of Gibraltar as Margaret Thatcher did looking after the interests of the Falkland Islanders."
Spain 'surprised' by war talk
Spain called for cool heads on Monday. Speaking in Madrid, the Foreign Minister, Alfonso Dastis, said the Spanish government was "surprised" by the tone of the comments. "Frankly, it seems to me that someone in the United Kingdom is losing their temper," he said.
Dastis noted that Howard had not explicitly said Britain should go to war with Spain, but said that bringing up the Falklands conflict was "a little out of context."
May called called Fabian Picardo, the chief minister of Gibraltar, on Sunday morning, Downing Street said, and told him that the UK was "steadfastly committed" to the territory.
British Foreign Secretary Boris Johnson said Brexit would bring no changes to the status of Gibraltar.
"I think the position of the government is very, very clear, which is that the sovereignty of Gibraltar is unchanged, and it's not going to change and cannot conceivably change without the express support and consent of the people of Gibraltar and the United Kingdom, and that is not going to change," he said.
Gibraltar, dominated by the 426-meter-high Rock of Gibraltar, is classified as a British Overseas Territory but it is mostly self-governing with a chief minister as its head. Britain provides some services, such as security, to the territory.
The UK has held sovereignty over Gibraltar for more than 300 years after it was captured from Spain in the Spanish War of Succession in 1704. Spain has recognized British rule under international law and in several treaties. Successive Spanish governments have raised talk of reunification since the 1960s, but in 2002, residents of Gibraltar rejected a proposal to share the territory between the UK and Spain in a referendum.
But residents also voted overwhelmingly to stay in the European Union in last year's Brexit vote, with 96% voting to remain in the union.