Spain has firmly rejected Angela Merkel’s attempt to secure an EU-wide quarantine policy for British tourists, as UK holidaymakers rushed to book flights to new “green list” destinations, including the Spanish islands of Mallorca and Ibiza.

The German chancellor fears that the Delta variant, which is dominant in the UK, could be spread across Europe by British tourists, especially now that Boris Johnson’s government is starting to allow UK citizens to travel again.

“In our country, if you come from Great Britain, you have to go into quarantine — and that’s not the case in every European country, and that’s what I would like to see,” Merkel said on Thursday.

But Spain has insisted that each EU country makes its own sovereign decision about who to admit, as is their legal right, and is desperate to see tourism reopen: the country’s income from tourists collapsed by almost 80 per cent last year to less than €20bn.

Traffic lights and data: how countries on the UK travel list compare Bubble sizes relate to the number of passengers flying directly to and from each country in 2019 As of Jun20 2021

Reyes Maroto, Spain’s tourism and industry minister, welcomed the addition of the Balearic Islands from next Wednesday to the UK’s green list, which allows quarantine-free travel on return.

However, there were indications that Madrid might toughen its current policy, which allows British tourists to enter the county without any medical documentation, as domestic concern increases about the Delta variant.

Francina Armengol, the head of the Balearics’ government, called on Spanish health authorities to impose “strict and safe entry controls” on UK visitors.

Officials in the regional administration said the same rules should be applied to British tourists as to visitors from other high infection areas — such as proof of vaccination or diagnostic tests. “We have fought a long time for the British to come, but they should come under the safest possible conditions,” said one, adding that intensive discussions would continue with the national government over the weekend.

Emmanuel Macron, French president, has also supported the EU taking “co-ordinated decisions in terms of opening of borders to third countries”, but there is no sign of a united front in Europe. A summit of EU leaders on Thursday night only stressed the need to continue vaccination efforts and “be vigilant and co-ordinated with regard to developments, particularly the emergence and spread of variants”.

Ursula von der Leyen, European Commission president, said on Friday that the EU was worried about the “rapidly progressing” variant and needed to stay “very co-ordinated” on measures to stop its spread.

Grant Shapps, UK transport secretary, said countries such as Germany were “more concerned” about letting visitors in because they had lower vaccination rates than countries like Malta.

Shapps has added 16 countries or territories to the green list from next Wednesday, including Malta, Madeira, Antigua and Barbados, but he refused to say whether he was planning a foreign holiday this year.

“Whoever is booking to go anywhere this summer, travel insurance, making sure your flights are changeable and making sure the accommodation is changeable — all those things are going to be very, very important this year,” he told Sky News.

The travel industry broadly welcomed the changes, but urged ministers to go further. Only Malta of the 16 destinations added to the green list is guaranteed to remain on the green list until the next review, on July 15.

The other destinations were put on a green “watchlist”, meaning they could be removed from the list at short notice at any point in the next three weeks.

Michael O’Leary, Ryanair chief executive, described the travel announcement as “a step in the right direction” but said the new green watchlist could cause confusion for passengers.

Prices for flights to some green list destinations have soared since the announcement. The cheapest one-way flight from London to Ibiza on July 1 is £220, up from £60 one day ago, according to Google data.

Airlines including easyJet, Ryanair and British Airways have rushed to add extra capacity to opened up destinations to keep up with demand. Travel agencies have also reported soaring interest in holidays to the Balearics and Malta.

However, transatlantic business travel is still effectively sealed off, with restrictions on arriving passengers in both the US and UK.

“The UK has already fallen behind the EU’s reopening and a continued overly cautious approach will further impact economic recovery,” said Shai Weiss, Virgin Atlantic chief executive.

Shapps confirmed that he hoped to open up quarantine-free travel to amber list countries for people with two jabs later in the summer; government officials say that is unlikely to happen before August though. Ministers are looking at whether to exempt children.

Airline shares fell on Friday, with British Airways owner IAG losing 2.5 per cent and easyJet down 1.5 per cent.