Travellers wanting to go on holiday this summer will "almost certainly" need to have a third Covid vaccine, the transport secretary said on Tuesday.
Grant Shapps said he has spoken to his counterparts around the world and it was likely that most popular holiday destinations will require travellers to have a booster jab to be considered fully vaccinated.
However the change is not likely to come in before the summer.
Currently having two doses of the vaccine is enough to arrive in England without having to isolate. From February 11 vaccinated travellers will no longer have to take a day two test.
Mr Shapps told LBC: "Increasingly countries elsewhere are requiring the booster for you to go there.
"So an important message for people listening, particularly perhaps younger people who maybe think 'Oh, I haven't bothered with the booster, I've been jabbed but I haven't bothered with the booster', get the booster because this summer, from talking to my counterparts around the world in Europe and elsewhere, if you want to travel, say go to Spain on holiday this summer, they are almost certainly going to require that booster jab.
"But for the time being fully vaccinated just means your first two doses, and that is it and you will use the NHS to show your status."
It comes as the Government announced changes to coronavirus travel rules.
All travellers will have to do is fill in a passenger locater form.
The changes will come in from 4am on February 11 in time for the half-term break.
Rules have also been eased for unvaccinated travellers, who will no longer have to take a day eight test or self isolate.
However, they will still need pre-departure and day two tests.
