Britons holidaying in the Algarve as the UK government put Portugal back on its "amber" travel list were confused and frustrated at the prospect of booking more tests and facing a ten-day quarantine upon returning home. "They give us the green light so we can come here, we go through all of the procedures to come here, and then they do this and I just think it"s really, really wrong," said Jasmine, visiting from Bristol. Britain removed Portugal from its green list for international travel on Thursday after just three weeks, citing rising case numbers and the risk of a virus mutation that had been detected in Portugal, also present in the UK. read more "I think it"s the worst decision ever," said Darren, who flew into Portugal from Liverpool. Like the other British tourists who spoke to Reuters he declined to give his full name. "While we"re on our holiday, we"ve got to start buying more tests for when we get home... it"s disastrous." Britons returning from Portugal from Tuesday onwards will need to quarantine for ten days and take two COVID-19 tests. Under green list rules, travellers would only need to take one test and did not need to quarantine. The UK government"s decision came as a huge blow to tourism businesses in Portugal, which had pinned hopes on the return of British tourists to revive the sector. Hotel owners and associations speaking to local media reported significant numbers of cancellations following the news. Portugal, which has reported a total of 851,031 COVID-19 cases and 17,029 deaths, has seen a slow rise in detected cases since it began lifting lockdown restrictions in May - but the government has also ramped up free testing in high-risk areas, particularly in Greater Lisbon. New cases are concentrated among young adults, Portugal"s health ministry has said, with hospitalisations remaining low and deaths per day near zero.