British holidaymakers face another scramble to return home to avoid quarantine after Croatia, Austria and Trinidad & Tobago were removed from the safe travel list.

Transport Secretary Grant Shapps announced on Thursday that travellers from those countries to the UK would be required to self-isolate for 14 days with the restrictions coming into effect from Saturday at 4am.

It comes as Portugal was given travel corridor status, meaning that Brits will not have to quarantine on their return to the UK from the country.

Prices for flights from quarantine nations rocketed following the announcement by Mr Shapps, with British Airways advertising tickets for an early Friday morning flight between Zagreb, Croatia to London at £276 for economy class. The same flight on Monday is £82.

Figures released by the Department for Transport (DfT) indicate that the weekly incidence (cases) per 100,000 for Croatia increased from 10.4 on August 12 to 27.4 on August 19, a 164% rise.

Over the same period, Trinidad and Tobago saw a 232% increase, while Austria had a 93% increase between August 13 and August 20.

In Scotland, travellers from Switzerland will also be required to quarantine for a fortnight on their return to the country.

Meanwhile, new figures reveal that less than a third of people in England being tested for coronavirus in the wider population are receiving their results within 24 hours.

The latest data on the NHS Track and Trace programme show that 60.5% of people who were tested for Covid-19 in the week ending August 12 at a regional site or mobile testing unit, a so-called “in-person” test, received their result within 24 hours.

Of those tested that week at a satellite test centre only 1.2% received their results within 24 hours while just 3.8% of people who used a home testing kits got results within 24 hours.

It comes as a group of MPs urged Boris Johnson to adopt a “zero-Covid” approach to tackling the virus across England.

In a letter to the Prime Minister, the All-Party Parliamentary Group on coronavirus said the measure would “provide clarity and reassurance” to the public.

Group chairwoman, Liberal Democrat MP Layla Moran, said: “The Government has failed abysmally to put a clear strategy in place to eliminate coronavirus from the UK.

“This lack of clarity has left the public confused and our NHS and care staff flying blind.

“The Prime Minister must get a grip and introduce a comprehensive plan to control this deadly pandemic before this winter.”

Mr Johnson is currently holidaying in Scotland with his fiancee, Carrie Symonds.

The Daily Mail has reported that the couple have been staying in a remote three-bedroom cottage on the Scottish coast.

The Prime Minister did not return from his holiday last week when exams chaos erupted after thousands of pupils had their results downgraded.

According to the Mail, Mr Johnson was offered the opportunity to make a public statement regarding the situation, but Downing Street declined.