Travel firms have welcomed the latest relaxation of quarantine rules, as 47 countries are taken off the “red list”.
But industry body Abta said it wants to see the government implement plans to replace expensive PCR Covid tests in time for the half-term break.
Airline Jet2 said there was a “genuine reopening” of international travel, with bookings trebling in some cases.
But the Welsh government warned the measures “considerably increase” the risk of importing new variants.
Under the latest changes, only Panama, Colombia, Venezuela, Peru, Ecuador, Haiti and the Dominican Republic remain on the UK’s red list – meaning that travellers from these places arriving in the UK must still stay in hotel quarantine for 11 nights at a cost of £2,285 for one adult.
Popular destinations such as South Africa, Thailand and Mexico are among the 47 places which will be removed from the red list on Monday at 04: 00 BST, making travel much easier and cheaper.
Jet2 chief executive Steve Heapy said there was “enormous” pent-up demand and customers are responding to the “assurance that the UK government is finally giving them”.
Virgin Atlantic reported a 150% increase in bookings to South Africa over the previous week, following Thursday’s announcement.
A spokesperson called the relaxation in travel rules a “positive step” but said the UK should follow the EU and US in eliminating all testing for fully vaccinated passengers from low-risk countries.
The government has announced plans to replace the requirement for a PCR test on day two after arrival, which can cost about £75 per person, with travellers to England being allowed to send a photo of a negative lateral flow test.
A government source said they intended to introduce this measure in time for the half-term break, which for many schools begins on 22 October.
Heathrow Airport said an announcement on when this would be implemented was “the missing piece”, adding that it is “critical in order to save the half-term getaway for many”.
Mark Tanzer, chief executive of Abta, said: “The reduction of the red list to seven countries is a sensible step forward in further opening up international travel.
“These changes along with the simpler system for travel means now is the best time in a long time to book and travel on a foreign holiday.”
But he urged the UK government to introduce the changes to PCR tests in time for half-term and called on the devolved administrations to implement similar changes quickly.
Scotland, Northern Ireland and Wales have all said they will also cut the number of countries on the red list to seven.
But Eluned Morgan, Wales’ health minister, said she was only taking this step because the open border with England made a separate travel policy unviable.
She said in a statement that the “radical reduction” in red list countries and the plans to use lateral flow tests for returning travellers would “considerably increase” the risk of new variants being introduced to the UK.
The latest measures also make it easier for travellers vaccinated in 37 countries – including Brazil, Ghana, Hong Kong, India, Pakistan, South Africa and Turkey – to travel to the UK.
As long as they have not visited a red list country or territory within the previous 10 days, they will be treated the same as fully vaccinated UK residents.
In full: 47 places removed from red list
The following destinations will be removed from the red list from 04: 00 BST on Monday:
Afghanistan, Angola, Argentina, Bolivia, Botswana, Brazil, Burundi, Cape Verde, Chile, Congo (Democratic Republic), Costa Rica, Cuba. Eritrea, Eswatini, Ethiopia, French Guiana, Georgia, Guyana, Indonesia, Lesotho, Malawi, Mayotte, Mexico, Mongolia, Montenegro, Mozambique, Myanmar, Namibia, Nepal, Paraguay, Philippines, Réunion, Rwanda, Seychelles, Sierra Leone, Somalia, South Africa, Sudan, Suriname, Tanzania, Thailand, Trinidad and Tobago, Tunisia, Uganda, Uruguay, Zambia and Zimbabwe.
Source: Department for Transport