Portugal and Malta have introduced measures to restrict UK travellers who are not fully vaccinated.The Portuguese government says travellers will have to quarantine for 14 days unless they can prove they received their second vaccine dose a fortnight before arrival.
Malta is also only allowing double-vaccinated people in from Wednesday.
In Spain, UK travellers need to prove they are fully vaccinated, or provide a negative PCR test on arrival.
Hong Kong is to ban all passenger flights from the UK from July 1, after the government said it had discovered cases of "variant virus strains".
The new quarantine measures apply only to those travelling to mainland Portugal, not Madeira.
There were 19 flights listed as departing on Monday from UK airports to Portugal's mainland airports - Lisbon, Faro and Porto.(BBC)