The news comes as Portugal announced that it was extending its ‘state of calamity’ until 30 May, throwing the holiday plans of thousands of Brits into doubt. The ban on non-essential from England will be lifted on Monday (17 May).

Healthcare company Salutaris People, which sells government-approved Covid tests, has warned of passenger confusion over Covid testing protocols to green-list destinations.

The company has also blasted transport minister Grant Shapps and the government for its “shambolic communication” of the traffic light system for travel and its green list of 12 designated countries.

It said that the transport minister and the government had failed to communicate testing and vaccination protocols for entry into the 12 designated countries, and which were open to receiving passengers from the UK.

It said this was going to leave airline passengers in complete confusion and disarray over which Covid tests they are expected to have for entry into their destination country and whether the country will even accept inbound travel and receive them.

Ross Tomkins, MD of Salutaris People, said: “The government communication around the ‘green list’ and traffic light system has only dealt with the quarantine restrictions for re-entry back into the UK. It has not communicated clearly and effectively what the entry and testing requirements are into designated countries.

“This, in itself, has created utter confusion for the public and airline passengers wanting to book holidays to those destinations. Many airline passengers will be thinking they don’t need to be tested – confusing re-entry protocols to the UK –  when in actual fact the destination country will have its own entry criteria for testing and vaccination. Some passengers may also confuse the existing NHS testing as a secure test result to be Fit to Fly. Many of the countries on the list are not accepting airline passengers into their country at the moment.

“In real terms we have had an announcement of 12 countries we can return from and a traffic light system, but no clear guidance on which countries will accept airline passengers and what their entry requirements are. It would have been far more sensible and logical for the transport minister and the government to have announced which countries will accept airline passengers and what the entry requirements to those countries are in respect of test types and vaccination.”

Portugal was the highlight of the green list announced last week. Other countries and territories on the list either have closed borders, are too cold, or don’t widely cater for tourists. Australia and New Zealand are on the green list, but neither will accept UK tourists until 2022 at the earliest.

Entry requirements into Portugal currently states that all passengers, excluding children under the age of two, travelling to Portugal must show a negative PCR test result at the time of boarding. The test must have been taken within 72 hours of departure and airlines are likely to deny boarding if a passenger fails to show proof of the test.

Holiday bookings to Portugal soared after the green list announcement. Extra flights have been put on by airlines from regional airports including Liverpool John Lennon Airport and Leeds Bradford to Portugal for next week.