Summer holidays abroad will be opened up for vaccinated Britons under plans being considered by the Government, The Telegraph understands.
Officials are drawing up proposals that could allow people who have had both Covid jabs to avoid having to quarantine on their return from amber list countries.
The change would effectively turn amber countries green for the vaccinated, opening up the possibility of quarantine-free travel to most major holiday destinations in Europe and the US.
The proposals to ease the restrictions for vaccinated people are said to be at an early stage. Matt Hancock, the Health Secretary, who has fought for tough border restrictions, is said to be "open" to the change.
"They haven’t definitely got there yet, but that’s the direction of travel," a senior source told The Telegraph.
It came as Boris Johnson was attacked by Tory MPs in the Commons on Wednesday over his failure to end Covid restrictions as expected on June 21.
On Wednesday evening, 49 Tory MPs rebelled against the Prime Minister to vote against delaying the final lifting of lockdown. Despite the rebellion, the Government won by 461 votes to 60.
A leaked memo also suggested officials were planning to keep the work from home instruction beyond the new July 19 date for the ending of restrictions.
The plans are expected to be ready to be discussed by the Cabinet Covid operations committee within the next fortnight, potentially in advance of a June 28 deadline when ministers have pledged to review the current traffic light system for testing and quarantining travellers.
Officials are still working on whether any new regime would be limited to returning Britons or apply to all arrivals, what exemptions there could be for those who could not be vaccinated and whether children under 18 should be exempted given that they will not have been jabbed by July 19.
"It is still at an early stage and it is not clear whether it will be worked out in time for the end of the month. There is an awful lot to do. The devil is in the detail," said a source.
A government spokesman said: "Recognising the strong strategic rationale and success of the vaccine programme, we have commenced work to consider the role of vaccinations in shaping a different set of health and testing measures for inbound travel."
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Changes to the current travel regime have been urged by Tory MPs and travel chiefs who fear the UK could lose out to Europe economically as it lifts restrictions for vaccinated travellers. On Wednesday, the EU added the US and Hong Kong, key trading partners, to its "white list" for jabbed visitors to avoid tests or quarantine.
Henry Smith, the Tory chairman of the all-party Future of Aviation group, said Britain would be an "outlier" if it did not adopt the same approach to vaccinated travellers as most other countries.
At least 33 countries, including Germany, France, Spain and Greece, exempt vaccinated passengers from quarantine.
"If we don’t do it, we will be at a significant disadvantage to our international competitors. Public health paranoia will have trumped common sense if we don’t go down that route," Mr Smith said.
Under the traffic light system, there are just 11 countries on the UK’s green list – of which Iceland, Gibraltar and Israel are the only viable holiday destinations.
Anyone travelling to them is exempt from quarantine but has to have a pre-departure test followed by a PCR test on return to the UK to enable health officials to detect any variants.
As well as 10 days of quarantine, any traveller returning from an amber country currently has to have a pre-departure test, then PCR tests on days two and eight of self-isolation, with the option of a test to release on day five.
Travel countries on the red, green and amber list
There is no date set for any change in the restrictions, although Boris Johnson has pledged to offer vaccines to all those over 18 by July 19. This would mean that by then no adult could face discrimination going abroad by not being vaccinated and having to continue to quarantine on their return.
It follows research by Public Health England (PHE), cited by the Prime Minister, which found the Pfizer vaccine was 96 per cent effective against hospitalisation with the delta Covid variant after two doses and the AstraZeneca jab 92 per cent effective.
Tony Blair, the former prime minister and an early proponent of vaccine passports, told The Telegraph on Wednesday that the Government should "bite the bullet" and introduce passports for domestic and international travel.
He said current government policy "literally makes no sense at all" in terms of the practicalities of travelling, the race to achieve herd immunity or day-to-day risk management of Covid infections.
Tim Alderslade, the chief executive of Airlines UK, said: "The welcome news from PHE that vaccines are highly effective against the delta variant following a full dose is further evidence that fully vaccinated passengers can safely be exempted from quarantine and testing restrictions from green and amber countries.
"This is already happening in Europe and across the world, and with two-thirds of UK adults expected to be fully jabbed by July 19, there is no reason why such a move cannot happen now to save the summer season and enable people to get away with their loved ones.
"This would be proportionate and data-driven and entirely consistent with the Government’s approach of using our vaccine dividend to safely unlock society and get the economy moving again."
Karen Dee, the chief executive of the Airport Operators Association, said: "The UK should follow the example of the US and the EU, who are reducing restrictions for fully vaccinated travellers, and give Britons their vaccine dividend."
John Holland-Kaye, the chief executive of Heathrow Airport, said: "The Government is confident that vaccinations are effective – so surely people who have been fully vaccinated should be able to travel without the need to quarantine or take expensive tests.
"The freedom of travel will not only incentivise people in this country to get vaccinated, it will also show other countries the benefits of scaling up their vaccination programmes."
On Wednesday, Mr Hancock told MPs that he backed a system of testing as a potential alternative to self-isolation for people who may have come into contact with Covid.