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.
Mr Shapps made the announcement in a bid to control the spread of coronavirus, with cases spiralling in those countries.
But passengers arriving in the UK from Portugal will no longer have to self-isolate after it was added to the travel corridor list.
The announcement saw prices for flights rise from the quarantine nations, with British Airways advertising tickets for an early Friday morning flight between Zagreb, Croatia to London at 308 euro (£276) for economy class.
An economy seat on a flight from Vienna to London Heathrow was advertised for 538 euro (£482) by the airline on Thursday night.
Flight prices from the UK to Portugal went up sixfold following the Government announcement, reports the Daily Mail. Average fare prices to Faro increased from £35 to £190.
Figures released by 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 per cent increase.
Over the same period, Trinidad and Tobago saw a 232 per cent increase increase in weekly incidence per 100,000, while Austria had a 93 per cent increase between August 13 and August 20 (from 10.5 per 100,000, to 20.3).
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 per cent 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 per cent received their results within 24 hours while just 3.8 per cent of people who used a home testing kits got results within 24 hours.
It comes as a group of MPs urged Prime Minister Boris Johnson to adopt a “zero-Covid” approach to tackling the virus across England.
In a letter to Prime Minister Boris Johnson, 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.
Additional reporting by PA Media.