LONDON - A former Spanish prime minister once described the rock of Gibraltar, which Spain ceded to Britain in 1713, as a stone in the shoe of Anglo-Spanish relations. But Gibraltar currently isn't the only source of Spanish irritation with the British.
Last week's abrupt decision by London to require Britons returning from vacation in Spain to quarantine for 14 days has angered a Spanish government desperate to salvage something from the wrecked summer tourism season. And it augurs badly for Britain's ongoing, fraught negotiations with the European Union for a post-Brexit free-trade deal.
The two governments have been at loggerheads since Prime Minister Boris Johnson and his advisers abruptly reintroduced the quarantine measures six days ago - to howls of protests not only from the Spanish government but also from Britain's struggling airlines and Spanish hoteliers trying to stave off bankruptcy.
Johnson's official spokesman warned "no travel is risk-free during this pandemic." Since then, Luxembourg has been added to Britain's list of risky countries to visit.
The Spanish government has been lobbying Downing Street to change its mind, pointing out that large parts of Spain, including the tourist hotspots of the Canary and Balearic Islands, are safer than Britain and have much lower coronavirus infection rates.
In an interview last week with the Telecinco TV network, Spain's Prime Minister Pedro Sanchez said his government was "talking with British authorities to try to get them to reconsider." He said Britain had made an error by lumping all of Spain together and not taking a more clinical and sophisticated regional approach.
He noted nearly 65 percent of Spain's new cases are occurring in two regions - Catalonia in the northeast and neighboring Aragon. Britain's quarantine requirement is "not well adjusted" to the epidemiological situation, he said. The Spanish point out that other European countries, notably France and Germany, have only advised their citizens against visiting Catalonia.
Under relentless pressure from Madrid, the British government says it will review in 10 days' time the quarantine requirement, which has prompted tens of thousands of would-be vacationers to cancel their travel plans. Low-cost airlines have halted flights to Spain. The review gives some hope to Spain that Britain may reverse its decision.
But Britain's quarantine decision is prompting a fierce backlash on the Iberian Peninsula that risks significant impact on Brexit talks.
Spanish ministers are fuming. They were given no warning by London. The Spanish see the move as a stab in the back. Britons account for more than a fifth of the 80 million tourists who visit Spain in average every year. Nearly half a million Britons own vacation homes in Spain. The Spanish tourism association has offered to pay for British travelers to take virus tests in Spain.
The dispute is threatening to reignite tensions between the two countries over the fate of Gibraltar, analysts say. Spanish politicians, goaded by the country's tabloid press, are warning that they won't do Britain any favors in the deadlocked negotiations over Britain's relationship with the EU. A key stumbling block in the negotiations is over fishing rights in Britain's waters.
Gibraltar could well be sued to further complicate Brexit negotiations. The current government in Madrid has dropped pushing Spain's sovereignty claim to Gibraltar, but it might revive it under pressure from Spain's parliament.
Gibraltar is desperate to ensure it will be able to benefit from a free-trade pact, if one is ever concluded, between Britain and the EU. Spain could wield a veto over that happening, shutting Gibraltar out of any easy relationship with the rest of the EU. Spain's EU Affairs Minister Juan Gonzalez-Barba warned last month, before the current spat, that talks over Gibraltar's future relationship with Spain and the EU "will not be easy."
And he hinted Spain could revive sovereignty ambitions. Ninety-six percent of Gibraltar's voters opposed Brexit in the 2016 EU referendum.
Spain's Iberian neighbor, Portugal, also is in dispute with Britain. Portugal was not included on Britain's safe-last of countries, which was first published last month. The country's foreign ministry blasted the exclusion, noting that 28 times more people had died from COVID-19 in Britain than in Portugal. An infuriated Antonio Costa, the prime minister, tweeted a graph illustrating it was safer in the tourist hotspot the Algarve, favored by British sun-seekers, than it was in Britain.
While Portugal has enjoyed centuries of good relations with Britain, Anglo-Spanish relations have been more uneasy, stretching back to Tudor times when Henry VIII offended Spain by ditching and humiliating his first wife, Catherine of Aragon. British piracy during the reign of Queen Elizabeth I in the "Spain Main" off the coastline of the Americas and in the Caribbean Sea set the scene for Spain's bid to invade England. But the Spanish Armada was defeated by legendary English seadogs like Sir Francis Drake.