Holidaymakers are braced for new travel restrictions as Greece and Portugal could become the latest countries to be added to the UK-wide quarantine list.

Pressure is mounting on England to consider imposing quarantine rules on travellers arriving from Greece amid reports of people returning with coronavirus.

Health Secretary Matt Hancock said a decision on whether to impose restrictions on the countries would be announced on Friday.

Rising Covid cases prompted the Scottish Government to announce travellers from Greece would have to self-isolate for 14 days from Thursday, while Wales began asking arrivals from the island of Zante to enter quarantine.

The UK’s biggest tour operator Tui has suspended its holidays to the resort of Laganas on Zante.

But Greece has insisted it is doing “everything in our power” to keep UK holidaymakers safe.

It comes as rising cases in Portugal were prompting many UK tourists to pay hundreds of pounds to fly home before Saturday.

In recent weeks, the Department for Transport (DfT) has announced changes to its quarantine exemption list on Thursday nights, with the new rules being imposed on Saturdays at 4am.

In Portugal, the seven-day coronavirus cases rate is 22.7, compared with 14.2 for the previous week.

A seven-day rate of 20 is the threshold above which the UK Government has considered triggering quarantine conditions.

There were 14.3 coronavirus cases per 100,000 people in Greece in the seven days to September 1, up from 14.1 a week earlier and a similar rate to the UK.

In Buckinghamshire, two groups of people have tested positive for coronavirus after returning from abroad – including a group of teenagers from the Marlow area who are reported to have been on a trip to Zante.

Buckinghamshire Council said some of them were pupils at Sir William Borlase’s Grammar School and all the affected households were self-isolating.

Tour operator Tui also said it was aware of a “small number” of positive Covid-19 test results following a flight from Heraklion in Crete to London Stansted on August 27.

One passenger on the flight, who had been contacted by NHS Test and Trace and asked to self-isolate, complained that “hardly anyone” on the flight had been wearing a mask.

The woman, who wished to remain anonymous, told the PA news agency: “Our flight was hideous, hardly anyone wore a mask and the crew didn’t do anything about it.

“We raised the issue twice with the cabin crew who still didn’t enforce it.

“My family is okay but we are having to self-isolate.

“I’m so sad for my son because he has to miss his first week back at school.”

A Tui spokeswoman added: “We can confirm that no guests tested positive for Covid-19 in our hotels and no symptoms were displayed before or during the flight home by any of the customers.”

It came after Public Health Wales confirmed at least 16 cases of Covid-19 from three different parties who were on Tui flight 6215 from Zante to Cardiff on August 25.

One traveller claimed that the flight was full of “selfish ‘covidiots’”, with passengers not wearing their masks properly and disregarding the rules.

In a statement, Tui said that cabin crew and other passengers confirmed there were multiple warnings about wearing face masks on the flight.

Meanwhile, the Guardian reported that officials had not notified Wizz Airline that eight passengers on a flight back from Crete had tested positive for coronavirus.

The teenagers, from Hampshire, were diagnosed after returning to London Luton airport on 25 August, it said.

But the Department of Health and Social Care said that it had taken action to advise the necessary people to self-isolate and its contact tracing team had been in touch with Wizz Air.