LONDON, June 21 (Reuters) - The aviation industry on Monday demanded that Britain removes COVID testing and isolation requirements for fully vaccinated travellers from most countries, a step already being taken in the European Union to help tourism recover. Airlines UK said in a letter to Transport Secretary Grant Shapps that fully vaccinated travellers from "amber" destinations should be exempt from the 10-day isolation requirement, while those coming from both "amber" and "green" countries should not need to have expensive PCR tests. "Given the incredible efficacy of vaccines and their critical role in easing domestic restrictions, we believe that the framework can safely be adjusted to provide a pathway for vaccinated people to travel without restriction, alongside steps to reduce restrictions for green and amber categories, making them more proportionate for travellers," the group said. British Prime Minister Boris Johnson said on Monday that travellers would face hassle and delays this year if they sought to go abroad because the priority would be keeping the country safe from the coronavirus. Data confirming that vaccines are more than 90% effective against hospitalisation from the fast-growing Delta variation should be considered when measures that apply to each tier of Britain"s traffic light system for travel are reviewed on June 28, it said. "This effectiveness has been recognised by Europe, which is now opening its travel and leisure markets by introducing waivers from testing and isolation requirements for fully vaccinated persons, including arrivals from major markets such as the United States," it said. "Today 32 countries exempt travellers from quarantine and 27 from testing if fully vaccinated. The failure to adopt a similar approach risks the UK falling further behind the EU"s reopening of international travel, including the critical trans-Atlantic market." Popular European holiday destinations for Britons, including Spain, Portugal, France, Italy and Greece, are currently rated "amber", which require returning passengers to take three COVID-19 tests and isolate for 10 days on return. The 11 countries and territories rated “green” require two tests for passengers, including those who are fully vaccinated.