"We know under this process Sussan Ley has refused .05 per cent of the projects that have come to her," NSW Shadow Minister for the Environment, and Port Stephens MP Kate Washington said.

"We are still very worried about the overall outcome."

Federal Environment Minister Sussan Ley delayed her decision on the proposed Brandy Hill Quarry expansion this week and will now hand down her verdict on October 13.

"We have got the extension but there is a lot more work to be done to make sure that Sussan Ley knows that the last thing she should be approving is the removal of critical koala habitat here in Port Stephens," Ms Washington said.

Ms Ley's office told The Mercury last week a University of Newcastle report, which found breeding koalas within a kilometre of the site, and the summer bushfires were being factored into the assessment.

In a Facebook post on Tuesday she noted the deadline had been extended "to ensure all information is considered".

"The Morrison Government is rolling out a $200 million investment in bushfire wildlife and habitat recovery and I want to ensure that any bushfire impacts are taken into account at Brandy Hill," she wrote.

Koalas were pushed back on the state agenda on Thursday when NSW National Party leader John Barilaro announced the party won't vote on NSW government bills due to a conflict over the State Environmental Planning Policies (SEPP) and its protection of koala habitat.

He says the policy changes are bad news for landowners and farmers.

Read more: Expert call to halt quarry plan

Read more: Resident bid to save 'critical' koala habitat

Read more: Proof is in the trees: Independent search finds breeding koalas

In an ironic twist the SEPP did nothing to protect koalas when it came to assessing the Brandy Hill Quarry expansion at a state government level. The legislation is irrelevant because the quarry is considered a State Significant Development due to its environmental impact. That's why Ms Ley has the final say on it.

"Labor opposed the weakening of the land clearing laws that they introduced and we have been urging the government to protect the environment ever since, but the reverse has happened," Ms Washington said.

The quarry project involves clearing 52 hectares of koala habitat to expand the rock quarry and increase production from 700 tonnes to 1.5 million tonnes per year.

A Facebook page, initially called '30 days to save Port Stephens koalas', has been instrumental in the fight against the expansion. It has attracted support from around the globe.

"What we've said is that it should not be possible to approve a project that will have a significant impact on a threatened species on the basis of data collected in 2014 and before planning instruments have been updated to take into account the fact that koalas in NSW are set to be extinct by 2050," founder Chantal Parslow Redman said.