Covid passports will be made available to prove people have been vaccinated as early as next month, in time for summer holidays, the travel industry has been told.
The Department for Transport wants an official certification scheme that gives British travellers a document they can show at borders overseas in place by May 17.
In a separate development, a European medical agency recommended that fully vaccinated travellers should be able to sidestep tests and quarantine.
It potentially smooths the path for holidays to more than 20 countries that have indicated they could ask travellers for proof of vaccination, such as Israel, Croatia, Turkey, Spain, Portugal and Cyprus.
Greece has moved to reopen its tourism industry by dropping quarantine rules for travellers from more than 30 nations if they have been vaccinated or tested negative for Covid-19.
The Covid vaccine certificate could come in either digital or physical form, with government officials exploring the best way to make it work in the tight time frame.
Critically, the proof of having received a Covid jab would be certified by UK Government, meaning it would be accepted by countries demanding evidence before entry.
The advanced state of the plans emerged after The Telegraph learnt of details of a telephone call between government officials and industry figures.
The call took place on Wednesday afternoon between members of the Tourism Industry Emergency Response Group and involved discussion of the latest thinking on border reopenings.
A government official on the call is understood to have said: “We aim to give people the ability to prove their vaccine status by the time international travel restarts where other countries require it. The earliest that will restart is May 17.”
The comment was noted during the call by one industry source. A second confirmed the broad accuracy of the remark. DfT sources did not dispute it.
The comment is in line with private briefings from government figures that the ban on overseas holidays is expected to be lifted on May 17 at the next stage of reopening.
However, for now, the Government is yet to lock in the May 17 return of overseas holidays, with a final decision expected to be taken early next month once more Covid case data are received.
It is understood that proof of vaccination, or Covid passports, will be designed to be used only for Britons flying out of the UK and into other countries.
A wider scheme to create an internationally recognised Covid vaccine certificate will take much longer to develop and is unlikely to be ready by May.
In Britain, attempts to convert an NHS app to show proof of vaccines, negative tests and antibodies may not be completed by next month, hence the interest in a more basic document.
Similarly, government interest in using Covid passports in domestic settings, especially for large events, is unlikely to lead to rule changes until June at the earliest.
When borders reopen, countries will be divided into green, amber and red categories, with testing required in the former and hotel quarantine in the latter. It is unclear how vaccination status will be factored into this system.
In a boost to holidaymakers, the European Centre for Disease Prevention and Control (ECDPC) said the risks were so low that requirements for testing or self-isolating travellers could be “waived or modified”.
It said the latest medical evidence showed the risk of a unvaccinated person contracting the virus from an inoculated individual was “very low”.
It also concluded, based on the latest available evidence, that there was no risk of severe Covid being contracted through transmission.
The ECDPC said: “Requirements for testing and quarantine of travellers (if implemented) and regular testing at workplaces can be waived or modified for fully vaccinated individuals.”
The only condition, it said, would be if there was the presence of Covid variants, which scientists are investigating for their potential to undermine the effectiveness of the vaccines.
It came as MPs demanded holidaymakers must be told the Government’s safe “green list” destinations by the end of next week – or risk jeopardising the relaunch of summer break.
The Commons transport committee has set a deadline of Saturday, May 1, for Britons to be told the list of countries where they could safely book holidays from May 17, the scheduled date for the resumption of foreign travel.