Coronavirus vaccine passports will exist by this summer for travel to the EU, Germany's leader has suggested.
Chancellor Angela Merkel last night said "everyone agreed that we need a digital vaccination certificate" at an EU summit.
She said the European Commission would need around three months to create the technical basis for such documents.
That suggests they could be ready as soon as the start of June, shortly after the May 17 earliest date for holidays to be allowed from the UK.
According to The Times, she added: "This will make travelling within the EU possible and could pave the way for further travel from third countries into the EU."
Since Brexit the UK is considered a 'third country' meaning there are tight restrictions on travel into the EU due to coronavirus.
A scheme allowing people to prove their vaccine status could open the door to holidays in the EU this summer.
Currently going on holiday from the UK is illegal, with travel only allowed for people with a reasonable excuse such as work.
A Global Travel Taskforce is due to review the current rules and report back by April 12 to give families time to plan their summer.
The ban on international holidays will not be lifted before May 17 at the earliest. Even when it is eased, it is possible families will still have to quarantine for 10 days on their return - which could include £1,750-a-head stays in a hotel.
Boris Johnson has ordered a review by Michael Gove to look at a system in the UK allowing people to show a vaccine passport.
This could include re-engineering the NHS Covid-19 app, downloaded more than 20million times, to show a vaccine or test result.
The PM has said he is happy to work on a passport scheme for foreign travel, though there are question marks about whether it will be used domestically for entry to theatres, cinemas, pubs or gigs.
