The instruction came from the United Nations as it ruled that the reef should not be added to a World Heritage danger list following a vehement campaign from environmental group Greenpeace to have it listed.

The Great Barrier Reef was given World Heritage status in 1981, and an ‘in danger’ listing from the United Nations Educational, Scientific and Cultural Organisation (Unesco) would have a severe impact on its annual A$6bn tourist industry.

It would also put a major question mark over plans to open more coal mines in Queensland and more coal ports along the coast – schemes which Greenpeace argues will put the fragile reef in even more danger.

A draft Unesco report says Australia must fulfil commitments to restore water quality and restrict port developments near the reef, and adds that it will continue to check on progress.

Australian environment minister Greg Hunt, quoted in the Courier Mail, said: “This is the strongest possible endorsement of what Australia and Queensland are doing. The decision could not be more categorical. It recognises not just the plan, but the real world improvements that are occurring.”

But Greenpeace said in a statement that the draft report was “not a reprieve – it is a big, red flag from Unesco”. The group’s reef campaigner, Shani Tager, noted that the Australian government had been asked to prepare a report within 18 months.

“Unesco now joins a long line of scientists, banks, organisations and individuals who are deeply worried about the reef’s health,” she said.

The Great Barrier Reef comprises 3000 coral reefs and 600 islands covering 348,000 sq km, and contains 400 varieties of coral, 1500 species of fish and 4000 types of mollusc. It attracts around two million tourists annually. But conservationists have warned that the outlook for the reef is “poor”, with a report last year predicting further deterioration as a result of climate change, extreme weather and pollution from industry.

Australia responded earlier this year by submitting its ‘Reef 2050’ plan to Unesco. This included a pledge to reduce pollution by 80 per cent before 2025, and the reversal of a decision to allow dredged material to be dumped near the reef.