Britain will confirm in early May whether it will allow international travel to resume from May 17 and which countries will fall into the red, amber or green categories in a traffic light system based on COVID-19 risks.Airlines, desperate for a bumper summer after a year of restrictions, criticised proposals from the government’s Global Travel Taskforce, which include COVID tests, saying the 100 pound cost of PCR testing for those arriving from low-risk green countries would put off many travellers.Giving new details of how it hopes to allow people to travel this summer, the taskforce also said work was going on to develop a certification system, sometimes called “vaccine passports”, for inbound and outbound travel.