Twelve international ambassadors to Unesco, including Australia’s, have written to the UN body to “share collective concerns” about its decision making, ahead of a crucial meeting that could see the Great Barrier Reef placed on a “world heritage in danger” list. A former Australian government world heritage official said the letter, sent to Unesco’s director general, Audrey Azoulay, on Wednesday, should be seen as part of the country’s promised lobbying effort as it desperately tries to avoid the reef being included on the list. On Thursday, Scott Morrison said Australia had been “busy talking to our friends”, listing the 11 other countries that signed the letter. The prime minister claimed Unesco’s process in recommending the Great Barrier Reef for the list had been “absolutely appalling”. On Wednesday, senior Unesco official Dr Fanny Douvere defended the process, saying the recommendation had been informed by science-based reports from the Australian government, including the Great Barrier Reef Marine Park’s 2019 downgrading of the reef’s long-term outlook. The letter is signed by Australia’s ambassador to Unesco, Paris-based Megan Anderson, alongside her equivalents from Indonesia, Canada, the UK, France, Thailand, Hungary, Poland, Bangladesh, the Philippines, Turkey and Spain. The ambassadors write that “we share collective concerns over the process taken to develop recommendations to be discussed at Unesco’s 44th World Heritage Meeting”. The ambassadors write that Unesco and its advisory bodies, which include the International Union for Conservation of Nature, had “limited ability” to “evaluate and analyse reports” or carry out site visits “particularly during the Covid crisis”. “However, we underscore the need for intergovernmental and international institutions to continue to apply due process in interactions with their States Parties.” Recommendations should be based on “transparent, extensive and close consultation processes”, the letter says, including for significant decisions “such as immediate in-danger listing of properties”. Morrison said the process of recommending an immediate listing was different the last time the Great Barrier Reef risked being added to the list, at a 2015 meeting. Before that meeting, a monitoring mission was carried out in 2012 before the committee recommended in 2014 the “possible inscription” onto the “in danger” list at the 2015 meeting. Dr Jon Day, a former Australian official at more than 10 world heritage meetings, said only three of the 12 countries that signed the letter – Hungary, Spain and Thailand – were current voting members of the 21-country committee. Australia is also a member, but would not be allowed a vote on its own property, he said. Day said: “This is part of Australia’s global lobbying effort to ensure the reef is not put on the danger list. This has happened every time the reef comes up [before the committee]. “Australia will be lobbying every country it can. But the committee has been saying this year after year, and the Australian government has been ducking and weaving.” The environment minister, Sussan Ley, has said the government was “blindsided” by Unesco’s recommendation, and said Unesco must have bowed to political pressure. Some media have speculated that pressure came from China – a claim dismissed by Douvere. Unesco’s recommendation says there have been three mass coral bleaching events caused by rising ocean temperatures since it last considered the reef – in 2016, 2017 and 2020 – and a lack of progress on reaching water quality targets. Those conclusions were based on official state and federal government reports and reviews by the Great Barrier Reef Marine Park Authority. Day, an adjunct senior research fellow at James Cook University, said the committee had previously “ducked the issue” of climate change. “The issue is that so much of the world’s heritage is being impacted, the committee can’t pretend any more that it’s not part of their mandate. They can’t ignore it.” The Guardian has approached Unesco for comment.