The federal government insists it is striving to avoid the Great Barrier Reef being listed "in danger" ahead of a crunch UN meeting, after rejecting a Senate recommendation to block new port developments near the World Heritage ecosystem.

The world heritage committee begins an 11-day conference in Cambodia this week, where the UNESCO body will review the status of various prized ecological areas.

The committee is expected to recommend that the Great Barrier Reef, which has been listed as a World Heritage site since 1981, be placed on the "in danger" list next year due to concerns over coal and gas expansion, increased shipping and water quality.

A draft World Heritage report produced in May noted "concern" over water quality monitoring and the lack of a "a clear commitment toward limiting port development to existing port areas". Unless "urgent and decisive action" was taken, the reef should be considered in danger, it said.

The federal environment minister, Tony Burke, told Guardian Australia improvements made since May showed the government was committed to safeguarding the Reef.

"I'm certainly hopeful that we can get some progress on what was in the draft report," he said. "We committed a further $200 million for Reef Rescue in the budget, which was since the report. That's one clear example of where they've expressed concern over water quality and we've acted.

"It'll be presumptuous to say what the world heritage committee will decide but I'm confident that we have evidence to show that Australia takes management of the reef seriously."

But Burke said the government would not support a Senate committee recommendation that a temporary halt be placed on new port developments in Queensland until an assessment, conducted by both state and federal governments, is released in 2015.

The committee, which considered a bill introduced by Greens senator Larissa Waters, said in its report that existing regulations "may not be sufficient to protect the Great Barrier Reef's outstanding values".

Burke said the move was unnecessary as there were no new developments planned before 2015. He said it was not straightforward to fulfill UNESCO's key recommendation of banning substantial new infrastructure outside existing port areas.

"I will follow the process properly, under law," he said. "If I pre-judge applications, it'll get thrown out in court. [UNESCO] understands the limits we have under Australian law. It's a nuanced situation.

"But they also understand that nothing has since been approved in pristine areas, and none was more sensitive than the proposed Xstrata development on Balaclava Island, which was cancelled after the draft report."

Fuel oil leaks from a Chinese bulk coal carrier grounded on the reef in 2010. Photograph: Getty

It is understood that several World Heritage delegates have been dismayed by what they see as a politicisation of the reef, with Burke involved in a series of public ructions with the Queensland government over the management of the vast coral ecosystem.

Last week, Queensland's deputy premier, Jeff Seeney, said Burke had been "held ransom" by "radical Greens".

"Mr Burke is beholden to the Greens who feed him dishonest and deceitful assertions about our government's actions," Seeney said. "It's time Mr Burke represented every person in this state, rather than those he believes will keep the Gillard government in power."

But Burke has also come under fire from the Greens and environmental groups, who accuse him of doing little to safeguard the reef and caving into the demands of the mining industry, with eight ports planned or expanded during his tenure.

Burke told Guardian Australia: "I find some of the political points quite bewildering. Jeff Seeney's comments were just odd, certainly one of the weirder moments in Australian politics. I can't understand what was going on in his head when he launched that diatribe.

"Larissa Waters, the Greens and Greenpeace are, in a large part, using the reef as a proxy for an anti-coal campaign. Those groups say the best way to limit emissions is to price carbon and then they ask for a regulatory mechanism too. They can't have it both ways."

Waters said it would be a "disaster" if the reef was placed on the "in danger" list, alongside sites predominantly found in developing or war-torn countries.

"Tony Burke isn't acting like an environment minister," she said. "He says a lot of strong things and then doesn't deliver.

"The UNESCO report was clear that there should be no new ports but there are no state or Commonwealth moves to limit these ports. Responsibility lies on both sides so it's farcical to see them pointing the finger at each other.

"It's amazing that it had to come down to me, a new member of the Senate, to draft a bill to protect the seventh wonder of the world because the government won't do it.

"The world heritage committee aren't idiots. This is their area of expertise. I imagine the Australian delegation will be pressuring other delegates to water down the criticism because it's embarrassing."

The reef faces a number of threats, including chemicals that flow onto it from agricultural land, a plague of crown-of-thorns starfish and climate change, which has been blamed for an increase in coral bleaching and severe weather events such as cyclones, which further damage the ecosystem.

Another potential risk is the dredging of the seabed to allow ships access to new ports. The Great Barrier Reef Marine Park Authority recently warned MPs that the impact of dumping dredging spoil onto the reef could be worse than previously thought.

The reef has lost half its coral cover in the past 27 years, the Australian Institute of Marine Sciences says. Last week, 150 Australian and international scientists signed a letter warning the reef was in crisis and required urgent action to protect it.

The Queensland environment minister, Andrew Powell, told Guardian Australia the state government's policy was consistent with UNESCO's demand for ports to be kept to existing areas.

"The Newman government firmly believes that we can have sustainable economic development and strong environmental protection – the two concepts are not mutually exclusive," he said.

"The Newman government is aware of the potential impacts of dredging which is one of the many reasons why we scaled back the previous Labor government's crazy proposals for a massive multi-cargo facility at Abbot Point."

"We want to ensure any development occurs in a considered and measured way and as such all development applications are subject to a stringent environmental impact assessment process."