THE Great Barrier Reef is set to be named as a World Heritage Site in danger by UNESCO next month.

A long-awaited assessment of the reef by UNESCO and the International Union for Conservation of Nature (IUCN), released on Friday evening, says decisive action must be taken to avoid a listing in June.

The report claims the federal and Queensland governments have failed to improve water quality or halt coastal developments that could impact the reef.

Only one annual water quality report card has been published, in 2011, which covered 2009.

A second report card was due in early 2012, but it's yet to be delivered.

The report also says there's been no clear commitment by the either federal or Queensland governments to limit port developments near the reef.

Instead about 43 proposals are under assessment.

"The above-mentioned issues represent a potential danger to the outstanding universal value of the property," the report said.

"The World Heritage Centre and IUCN ... recommend that the committee consider the Great Barrier Reef for inscription on the list of World Heritage in Danger ... in absence of a firm and demonstrable commitment on these priority issues."

Prime Minister Julia Gillard said the Federal Government was committed to keeping the reef a great heritage area for the world.

''In the last couple of weeks I announced a $200 million reef rescue commitment,'' she told reporters in Melbourne.

''We are very committed and we'll continue to pursue those kind of commitments in the future.''

But Greens Senator Larissa Waters called on Liberal and Labor to support a Senate bill which would adopt the World Heritage Committee's recommendations as law.

"The Newman and Gillard governments have continued to fast-track mega industrial ports alongside the reef," she said.

"Protecting the Great Barrier Reef must be beyond politics and all parties should support my bill."

World Wildlife Fund spokesman Richard Leck said UNESCO had put Australia in the sin bin.

"We will likely see a reef showdown this June," he told AAP.

The only other world heritage sites in danger that aren't in a developing country or an active war zone are the UK's Liverpool Maritime Mercantile City and Florida's Everglades.