The critically endangered Leadbeater's possum is being "monitored into extinction" while logging continues in its habitat, Greens senator Janet Rice claims.
Senator Rice took government officials to task in a Senate hearing on Tuesday over delays in emergency intervention, first demanded in 2015 and then in 2016.
The intervention plan is still in draft form and expected to be finalised in December.
The possum, native to forest areas north-east of Melbourne, was listed tenth on the Zoological Society of London's list of mammals on the brink of extinction this year.
"That's right up there with species like the Black Rhino," Senator Rice said.
The possum is currently listed as critically endangered but a biodiversity conservation official said its habitat is in a regional forestry agreement area.
Environment department deputy secretary Dean Knudson said the delays were the result of wanting to make a well informed and appropriate decision.
He said the Victorian government had put in place steps to protect the species and those steps were being considered with the latest science.
But Senator Rice accused the department of "monitoring the Leadbeater's possum to extinction".
"You've got logging continuing while these processes continue and the science is clear," Senator Rice said.
The possum was thought to be extinct until 1961.