- Climate change
image copyrightGetty Imagesimage captionThe Great Barrier Reef has held World Heritage status since 1981
The Great Barrier Reef should be put on a list of World Heritage Sites that are "in danger" over harm caused by climate change, Unesco says.
The UN's cultural body says the world's biggest coral reef system should be downgraded to the list at a meeting next month.
It is urging Australia to take "accelerated action" on global warming.
But the Australian government said it would "strongly oppose" the recommendation.
The latest row is part of an ongoing dispute between Unesco and the Australian government over the status of the reef, which gained World Heritage ranking in 1981. Unesco had debated whether it go on the in danger list in 2017.
Environment Minister Sussan Ley said the government had been "stunned" by the latest announcement, calling it a "backflip on previous assurances from UN officials" that the step would not be taken.
Rising sea temperatures as a result of global warming caused by the burning of fossil fuels are the main reason the reef has been severely damaged, scientists say.
There have been several "bleaching" events on the reef in the past five years.
media captionThe second bleaching is causing concerns over the reef's long term health.
The Unesco report says despite efforts by the Australian government, key targets on improving water quality in the reef had not been met.
If the recommendation is followed, it would be the first time a natural World Heritage Site has been placed on the "in danger" list mostly because of impacts from climate change.
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Listing a site as "in danger" can help address threats by, for example, unlocking access to funds or publicity.
But the recommendation could affect a major tourism destination that creates thousands of jobs in Australia.
China currently chairs Unesco, and there is some speculation that long-running tensions between Beijing and Canberra may have influenced the decision.
But environmental groups rejected any suggestion the recommendation was political.
"The recommendation from Unesco is clear and unequivocal that the Australian government is not doing enough to protect our greatest natural asset, especially on climate change," said Richard Leck, Head of Oceans for the World Wide Fund for Nature-Australia.