England will give two weeks' notice to would-be travellers if a country is under consideration for removal from its quarantine-free green list, Transport Secretary Grant Shapps said.
Hopes have risen that as many as 24 destinations could be declared “green” if the ban on foreign travel is lifted on May 17 under proposals for a traffic light-style system.
Travel corridors are suspended in England and currently, only British and Irish citizens, or those with residency rights, may enter. They must quarantine for 10 days.
Anyone who arrives from a red list country, or who has been in one within 10 days of travel to England, must quarantine in a government-approved hotel at their own expense.
The UK government is expected to revise its system for travel to England next week. It could introduce a "green list" of countries from which residents British and Irish citizens arriving in, or returning to, England would not have to isolate.
Scotland, Wales and Northern Ireland operate separate quarantine systems.
Mr Shapps confirmed in the House of Commons on Thursday the system would be based on four tests, including vaccination rates, the number of new infections, the prevalence of “variants of concern” and the quality of testing data.
He said the government “would flag perhaps a couple of weeks in advance” if a country was at risk of being removed from the green list.
Mr Shapps said the cost of Covid-19 tests could drop to £45 ($62) after public pressure on private operators.
But other areas of concern could hinder the widespread return of foreign travel for people living in England.
John Holland-Kaye, the chief executive of Heathrow Airport, said a lack of Border Force officers was leading to queues of up to six hours at customs.
He suggested planes could be diverted to other European cities such as Paris or Frankfurt if the system became overwhelmed.
Mr Shapps said the government was considering a digital system to check Covid-19 documents.
“It is the case that Border Force are checking currently every single person who enters the country to make sure they completed the pre-departure test and the locator form to say where they’ll be, so I’m afraid at the moment it is the case that that inevitably creates some queues,” he said.
“As we move towards the unlocking of international travel we will be addressing this issue, not least through beginning to automate the electronic e-gates with the pre-departure form.”
It is understood that a country would need to achieve a Covid-19 vaccination rate of at least 40 per cent of its population to be eligible for the green list.
Analysis by travel consultancy The PC Agency, based on current infection rates and vaccination take-up, found that as many as 24 countries could be placed on such a list.
Paul Charles, the company’s chief executive, predicted much of Europe and the US would feature on the list by June.
“Good news for holidaymakers,” he tweeted.
Johan Lundgren, the chief executive of budget airline easyJet, urged the UK government to declare most European states green within months.
“It’s not just for ourselves – it’s consumers and customers who need clarity if they can make their booking for summer, to go on a holiday, to go and see their family members they haven’t seen in over a year,” he said.
He repeated concerns that the system could become overwhelmed if there are not enough border officers.
“They need to have the resources to do their jobs,” he said.
On Friday, easyJet published research it commissioned that suggests travel would have a limited effect on Covid-19 hospital admissions in the UK.
The research, undertaken by epidemiologists at Yale University, showed unrestricted travel from much of Europe would increase hospital admissions by 4 per cent.