Millions of Britons could be barred from entry to the EU in the New Year unless they renew passports.
Visas will not be needed for short tourist trips whether or not there is a Brexit trade deal, but fears have been raised that large numbers of people could still be caught out when the transition period ends on January 1.
UK passports are currently valid in the EU and other countries in the Schengen free movement zone right up until their expiry date.
However, from January they must have at least six months left to run.
This means that those whose passports expire in the summer of 2021 will be unable to travel in the spring.
UK passports are currently valid in the EU and other countries in the Schengen free movement zone right up until their expiry date
Britons whose passports expire in the summer of 2021 will be unable to travel in the spring
Pets face new travel restrictions, warns minister
Pet owners planning to take their animals with them on holiday to Europe will face new restrictions from January 1, a Government minister has said.
Environment Secretary George Eustice said owners will not be able to use their EU pet passports once the current Brexit transition period finishes at the end of the year.
Instead, he expected they would have to get a certificate from a vet confirming their pets' rabies vaccinations were up to date before travelling.
However he indicated UK owners should avoid more onerous restrictions which would have meant obtaining a blood sample and sending it to an EU-approved laboratory at least three months in advance.
The Government had applied for the UK to be in Part 1 of the EU Pet Travel scheme, which would have meant little change to the current arrangements, however Mr Eustice said it was more likely to be in Part 2.
Crucially, people whose passports do not expire until the end of 2021 or even the start of 2022 might also be at risk of falling foul of the rules.
That is because UK passports can last up to 10 years and nine months rather than the standard 10 years - in recognition that renewal can happen when there is still time left on an old document.
The EU is set to ignore the extra nine months as well as the final six when it decides if a passport is valid.
The UK Passport Office issues five million every year, although it is not clear how many of those are new documents and how many renewals.
Experts have been warning that even with valid passports there could be delays at borders because Britons will have to queue with other non-EU nationals.
They could also need to show officials a valid return ticket and proof that they have enough money for their stay.
Visas will not be needed for tourist trips, buy stays will be limited to 90 days in any six-month period - potentially causing problems for holiday home owners.
The issues have been made worse as Passport Office branches have been closed for face-to-face due to coronavirus.
According to the Sunday Times, Simon Rippon, a professor of philosophy working in Austria, was told it might take eight weeks to renew the passport of one of his children.
'There will be a lot of people sent home from their flights because they didn't know they needed to have a passport that fits the new criteria,' he said.
Mr Rippon complained about text message reminders being sent out by the Passport Office, with vague wording such as: 'Passport validity rules will change from Jan 1, 2021, you may need to renew earlier than planned.'
Rules are also expected to change for pets, with Environment Secretary George Eustice today saying owners will now have to get a vet's certificate to prove their animal's vaccinations are up to date. Pet passports, which allowed EU travel, will no longer be valid.
Boris Johnson (pictured last week) is trying to strike a Brexit trade deal with the EU - but the travel rules are set to change regardless of whether he succeeds