The UK quarantine rules and advice for travellers arriving from Spain are "disproportionate", the country's prime minister has said.
It comes after the Foreign and Commonwealth Office (FCO) changed its guidance to include the Canary Islands and the Balearic Islands in its advice to avoid all but essential travel to Spain.
Anyone travelling from those locations to the UK must quarantine for 14 days.
The self-isolation rule was announced on Saturday, but many had hoped Spain's islands would be exempt due to their low coronavirus rates, unlike three hotspots on the mainland.
Speaking on private television channel Telecinco on Monday evening, Pedro Sanchez said although there are two worrying outbreaks, holiday islands like the Balearics and the Canaries, are safe to visit.
Mr Sanchez said the two governments had strong economical, political and commercial ties and appeared to hint about post-Brexit agreements.
"There are also negotiations that are happening that will be very important in the coming months for the relationship of the UK with the European Union," he said.
Talks between the two governments are ongoing.
What prompted the FCO's turnaround on Spain?
The government has been criticised for announcing mandatory quarantine rules, without warning, on Saturday evening - just hours before they were due to come into effect - and also told to get a grip on summer holiday "confusion".
Labour criticised the "chaotic nature of the decision making" but Number 10 has defended the last-minute move, saying border measures and travel advice can be "changed rapidly" in order to protect the UK from coronavirus.
The Prime Minister’s official spokesperson said: “Unfortunately no travel is risk-free during this pandemic and disruption is possible and so anyone travelling abroad should be aware that our travel advice and exemption list is under constant review as we monitor the international situation.”
Spain had been experiencing a rise in coronavirus cases for several days, but the government said it received the most recent data on Friday and the Joint Biosecurity Centre conducted an "urgent review" before advising to mitigate travel from midnight Saturday.
Holiday firms and the opposition urged the government to bring more clarity to the situation as travel companies cancelled flights.
There are now fears more European holidays could be thrown into disarray, with fears other countries could be struck off the 'air-bridges' list at potentially short notice.
It comes after the World Health Organization warned the pandemic "continues to accelerate" around the world, with nearly 16 million cases confirmed and more than 640,000 dead.
Both France and Germany are experiencing a spike in cases, prompting many to worry they could be next.
Close to 1.8 million holidays are likely to have been thrown into chaos by the move to remove Spain from the list, according to travel company The PC Agency.
The FCO's decision to include the Balearic and Canary Islands in its warning against all but essential travel came after Downing Street warned “no travel is risk-free”.
Travel firm TUI UK cancelled all holidays to the Balearic Islands and Canary Islands after the FCO’s updated travel advice against all but essential travel to all areas of Spain.
TUI’s decision runs from Tuesday, July 28, up to and including Friday, July 31.
Holidays to Spain’s mainland were were already cancelled from Sunday, July 26, up to and including Sunday, August 9.
“All customers due to travel to Spanish destinations between Sunday, July 26, and Sunday, August 9, will be able to cancel or amend their holiday and will be able to receive a full refund or the option to rebook their holiday with a booking incentive,” TUI UK said.
The company added: “The UK government must work closely with the travel industry as this level of uncertainty and confusion is damaging for business and disappointing for those looking forward to a well-deserved break.”
The situation elsewhere in Europe
Jet2 also said that it was cancelling flights to a raft of destinations in Spain from Tuesday after the FCO announcement.
Rory Boland, Which? travel editor, said: “This is the third announcement we’ve heard from the government regarding travel to Spain in the last three days.
"Hundreds of thousands of UK holidaymakers in Spain or about to fly are utterly confused.”
Labour said the government must abandon its one-size-fits-all approach and introduce sectoral support for struggling businesses to ensure that public health measures like the change in quarantine rules for people returning from Spain do not lead to mass job losses.
Labour’s shadow transport secretary Jim McMahon said: “The government’s handling of this issue has been nothing short of chaotic.
"The airline industry and passengers need clarity.
“The government must focus support on the sectors that desperately need it, like aviation, aerospace and its supply chain, which supports almost a quarter of a million jobs, with strict climate conditions and ensuring the gains are shared with the public.”
Cases in Spain
The announcement of the government’s new Spanish travel warnings came after Prime Minister Boris Johnson’s official spokesperson said decisions on border measures and travel advice “can be changed rapidly if necessary to help stop the spread of the disease”.
He went on: “Unfortunately no travel is risk-free during this pandemic and disruption is possible and so anyone travelling abroad should be aware that our travel advice and exemption list is under constant review as we monitor the international situation.”
Transport Secretary Grant Shapps is coming home early from a trip to Spain after the quarantine decision.
Mr Shapps told The Sun: “I think it’s right to get back to work in the UK as soon as possible to help handle the situation.
“The sooner I get back from Spain myself, the sooner I can get through quarantine.
“So, I’m leaving my family to travel back to the UK on Wednesday.”
Meanwhile, the Daily Telegraph reported that quarantine for people arriving from Spain or other countries with high coronavirus levels could be cut to ten days under plans being looked at by ministers.
Returned travellers would need to quarantine for eight days before being tested, and then only remain in quarantine for another two days should they test negative.
The paper reports the Government is also considering instructing everyone who has returned from Spain since July 23 to get tested.
The government is urging employers to be “flexible” in allowing staff to work from home while self-isolating and it expects the majority of people were expected to comply with quarantine rules.
Three fines have been issued at the border since the measures were first introduced in early June.
While the government wants employers to support staff caught up in the rule change, it has not extended any new support of its own.
The Trades Union Congress had been calling for Statutory Sick Pay to be extended to anyone forced to quarantine who cannot work from home.Downing Street said holidaymakers who miss out on work because of the quarantine period may be eligible for Universal Credit or employment support allowance but not statutory sick pay.
Pressed on whether ministers would review statutory sick pay eligibility, he said: “We always keep our response to the pandemic under review and we regularly assess the support available but there is support available for those in need.”
Under the rules employers are able to ask staff to cancel holidays if it means they will be out of work longer than planned, but the government says any worker who loses their job can appeal to the Advisory, Conciliation and Arbitration Service (Acas).