A key crossbench senator wants to pump the brakes on legislation aimed at speeding up environmental approvals.
Tasmanian senator Jacqui Lambie is not yet willing to hand Commonwealth responsibilities for environmental assessments to the states.
The one-touch model was recommended by businessman Graeme Samuel in a major review of the Environment Protection and Biodiversity Conservation Act.
The federal government could bring the proposed changes before the Senate as early as next week.
But Senator Lambie wants to see Mr Samuel's final report before making a decision.
She also wants the bill referred to a Senate inquiry for closer scrutiny.
These delays would stall the legislation until next year.
"This is a pretty important bill and it also needs to go to an inquiry," Senator Lambie told ABC radio on Wednesday.
"I don't want this going for months and months but it certainly needs to go through the right Senate process and it needs to go to an inquiry, there's no doubt about that."
Senator Lambie also questioned the capacity of states to handle environmental approvals, citing the management of a proposed wind farm project in Tasmania.
"I tell you what, the state of play down here, with how long the state government has taken to tick anything off through its incompetence blows me away," she said.
"Whether they don't have the staff, they are not set up properly, so I want to know how the states are going to handle all of this, and that's a real worry to me."
Senator Lambie said the wind project could create thousands of jobs in her home state.
"I'm having to basically slap the state minister down around here to get things moving," she said.
"You've got to ask whether this is the correct way to go forward."