Travel operators are laying on extra flights and calling for the Government to put more countries on the quarantine-free green travel list to cope with pent-up demand for holidays. Industry chiefs have criticised the “'overly cautious” approach of ministers in only approving 12 destinations so far. Portugal, Gibraltar and Israel are among the small group of countries which will be on the green list from May 17, with these three, as well as Iceland, allowing Britons in without the need to quarantine. The green list also features several remote British Overseas Territories and destinations where visits are heavily restricted, such as Australia, New Zealand, Singapore, Brunei and the Faroe Islands. EasyJet announced it has put over 80,000 extra seats on sale from the UK to green list destinations to serve demand for travel this summer and will relaunch a route from Newcastle to Faro. It said it is providing more flexibility for flights and holidays than ever before to help holidaymakers cope with the situation. The airline’s chief executive John Lundgren said the decision to put so few European countries on the list was “simply not justified by the data or science”. He said: ““We are disappointed that so few countries were put onto the green list as it is simply not justified by the data or the science and is inconsistent with the approach to reopen the domestic economy. “However, easyJet is the biggest operator from the UK to the European countries which are currently on the Green list, and we have increased our flights to these destinations where we can in order to take as many customers away as possible to reunite them with friends and family or on a long-awaited holiday – and we are ready and able to ramp up.” The chief executive of EasyJet Holidays, Garry Wilson, added: "We believe, looking at the science and looking at the data, that places like the Greek Islands, the Balearic Islands and the Canary Islands, very popular holiday destinations, actually do meet those criteria and should be on that list." Tui, the UK's largest holiday company, reported a sharp a rise in customer demand in the wake of the announcement, particularly for trips to Portugal. A spokeswoman said: "We've had the best day of sales for summer 2021 holidays since the initial road map announcement in February. Sixty per cent of all holidays sold yesterday were to Portugal." The firm said new flights and extra holidays have been added for people who want to "get away as quickly as possible". People returning to England from a green destination from May 17 will not be required to self-isolate and are only required to take one post-arrival coronavirus test. Transport Secretary Grant Shapps said the removal of the ban on international leisure travel is “necessarily cautious''. But Virgin Atlantic called for the US to be added to the green list, while the iindustry body Airlines UK urged the Government to make “major additions” to the green list at the next review point in three weeks. A Virgin Atlantic spokesman said of the quarantine-free list: “There is no reason for the US to be absent from the green list. This overly cautious approach fails to reap the benefits of the UK's successful vaccination programme.” Airlines UK chief executive Tim Alderslade said: “This is a missed opportunity and, with so few countries making it on to the green list, represents a reopening of air travel in name only. “By contrast, the EU has said vaccinated people will be able to travel without restrictions, which leaves the UK at risk of falling behind and not opening up international travel to key markets across Europe as well as the United States.” Brian Strutton, general secretary of pilots' union Balpa, accused the Government of an “excess of caution”, adding: “'Almost all tourist hotspots in Europe, including Spain, France and Greece, are in the amber category, which is as good as red as far as most tourists are concerned, with potential 10-day quarantine needed on return.” “Tourists are sat gazing at the amber light, revving their engines, desperate to travel safe in the knowledge that their jabs will protect them. The Government must flick those amber lights to green as soon as it possibly can.” The unveiling of the green list led to prices for a return ticket from London Heathrow to Portuguese capital Lisbon to soar from £264 before the announcement to £332 afterwards.