Portugal will be removed from England’s travel ban red list, the Department for Transport (DfT) said.
The decision means returning travellers will be able to quarantine at home, rather than in a hotel at a cost of £1,750.
But Ethiopia, Oman, Somalia and Qatar have been added to the red list to “protect the country against new variants of Covid-19”, the DfT said.
The changes come into force at 4am on Friday.
Portugal’s Algarve region is a popular hotspot destination for UK holidaymakers.
Foreign leisure travel could be permitted for people from England from May 17 under Boris Johnson’s road map for easing lockdown restrictions.
The DfT said it has decided to axe its ban on direct flights and sailings from Portugal – including Madeira and the Azores – due to “evidence that shows the risk of importing a variant of concern from these destinations has reduced”.
Portugal was initially added to the red list partly because of its connections with South America.
But the DfT said the country has “put steps in place to mitigate the risk from its links with countries where variants have become a concern”.
Mauritius will also be removed from the red list.
People who have spent time in a country on the list in the previous 10 days are banned from entering England, unless they are British or Irish citizens or have residency rights.
Anyone entitled to enter must stay in a Government-approved hotel for 10 days.
Qatar’s international airport is popular for people returning to the UK on connecting flights from countries in Asia and Australasia, so its addition to the red list will have a significant impact.
A travel ban is already in force for the United Arab Emirates, which is another Gulf hub.
The Government’s Global Travel Taskforce will provide a report to the Prime Minister on April 12 setting out recommendations for how and when foreign holidays could resume.
Turkey expects to welcome UK holidaymakers this summer without requiring proof of a vaccine or negative test.
Tourism minister Mehmet Ersoy said the country is “looking forward to welcoming British tourists with open arms”.
He went on: “We will not require vaccination passports from international travellers when entering the country.”
After April 15, Turkey will also re-evaluate whether visitors must continue to produce evidence of a negative PCR test taken within 72 hours of their departure.
Mr Ersoy said: “I expect there will be no such requirement from British visitors as the UK Government is rapidly and impressively rolling out the vaccination programme for the whole nation, and a significant portion of the population will be vaccinated by early summer.”
He added that employees at hotels and other tourist facilities in Turkey will be prioritised for Covid-19 jabs before the summer season.
Turkey’s plan not to require proof of a vaccine or test is in contrast to other hotspots popular with UK holidaymakers.
Greece will require international tourists to have been vaccinated, had a recent negative Covid-19 test or have coronavirus antibodies.
Visitors to Cyprus must have had both doses of a vaccine.