It was another blow to the tourism industry as it prepares to restart foreign travel on Monday to the 12 countries on the list announced last week.
The Prime Minister told last night’s Downing Street press conference: ‘We will certainly be making sure that people travelling abroad will be subject to all the tests and constraints to prevent the virus being reimported.
‘That’s why it’s such a tiny list of countries and I don’t expect we will be adding to it very rapidly. We will be maintaining a very, very tough border regime for the foreseeable future. It is just too early to talk about exactly what the summer will be like.’
He urged people to ‘think twice’ about travelling, especially if they are in an area with higher rates of the Indian variant.
Mr Johnson said: ‘We want people in those areas to recognise that there is extra risk, an extra threat of disruption to progress caused by this new variant and just to exercise their discretion and judgment.
‘The same spirit of caution should be applied to people who are thinking of travelling abroad.’
His downbeat outlook came as 18 airport bosses signed a letter urging Mr Johnson and his counterparts in the devolved governments of Scotland, Wales and Northern Ireland to initiate ‘a more meaningful restart of travel’.
They wrote: ‘We believe the current extremely limited green list of countries demonstrates that the UK is being overly cautious and will fail to grasp the opportunities resulting from the successful rollout of the vaccine.
‘There are a million jobs in aviation, with a further half a million jobs relying on aviation in the tourism sector. This is quite apart from the many sectors that need aviation in order to trade with both existing and new, developing markets. With the current restrictions the Government is applying, those jobs remain at very high risk.’
They warn ‘serious failures to manage the border’ also threaten the recovery. There have been queues of up to seven hours at Heathrow as border guards check passengers’ Covid paperwork manually and electronic passport gates remain closed.
Home Office officials are racing to integrate passenger forms with e-gates to reopen them for summer but the airport bosses fear this will not be done in time.
The bosses - from airports including Heathrow, Gatwick, Cardiff, Belfast International and Edinburgh - wrote: ‘Without a thriving aviation sector, the Government’s economic recovery and its ambitions for a global Britain and to level up the UK regions will be undeliverable. We need Governments to act now.’
The Government has said it will review the green list every three weeks, with the first in the week leading up to June 7. Transport Secretary Grant Shapps said the reopening was ‘necessarily cautious’ to stem the importation of mutant Covid variants.
Portugal and Gibraltar are the only countries on the list that most Britons will realistically be able to visit soon. Many other destinations are remote or have strict entry measures or blanket bans on UK tourists, such as Australia and New Zealand.
A Government spokesman said: ‘We recognise the challenges the travel industry has faced… and have supported the sector with around £7billion for loans and job retention schemes.’