The group tasked with drawing up the government's cornerstone energy policy may not have the resources it needs to get the job done in time.
The government expects the National Energy Guarantee to be ready for approval by state and territory ministers by August.
But the Energy Security Board may be struggling with the tight time frame.
Quizzed in a Senate hearing on Tuesday, energy department deputy secretary Rob Heferen denied reports the board was significantly under-resourced, but raised timing as a potential problem.
Greens senator Richard Di Natale raised a report by the Australian Financial Review claiming the board sent stakeholders a letter about needing "significant additional resources" to deliver the plan by August.
Mr Heferen said the board was resourced properly and didn't know why the comments, attributed to ESB deputy chairwoman Clare Savage, had been made.
"I had a conversation with her yesterday. We've discussed resources. It might be a time-frame issue," Mr Heferen said.
The letter was reportedly sent to stakeholders including the Australian Industry Group and Origin Energy, which have a stake in the outcome of the guarantee.
Government minister Simon Birmingham said the board would effectively manage any conflict of interest.