Modelling about how Australia's hospitals will cope with rising coronavirus cases is remaining secret until a federal-state deal is reached.
The Morrison government has refused to release the data, arguing all states and territories need to agree on its release.
Senior health officials including Chief Medical Officer Paul Kelly on Wednesday expressed confidence systems would cope with a spike in cases when Australia reopens.
He said real-world experiences in NSW and Victoria - where outbreaks started while vaccination coverage was lower - showed other states would be well placed.
"Intensive care has not been anywhere near overwhelmed as some have predicted. I feel very confident on that basis," Professor Kelly told a Senate estimates hearing in Canberra.
National hospitalisation numbers have improved despite high case numbers in Victoria over the past two weeks.
There has been a 15.5 per cent decrease in ventilated patients, an eight per cent fall in people needing intensive care and a 7.6 per cent drop in those in hospital.
"It has nowhere near exceeded capacity," Professor Kelly said.
But Labor senator Katy Gallagher believes the public should be shown the data underpinning officials' assurances.
"You all seem very confident. I think it's about time that we actually see what you all know and what the prime minister knows," she said.
Health secretary Brendan Murphy said a decision on whether all governments would agree to release the modelling was for national cabinet, which is due to meet next on November 5.
"The Commonwealth is happy to release it but it contains state and territory specific capacity data," he said.
"We are not opposed to releasing it at all."
Aged Care Service Minister Richard Colbeck denied the government was hiding behind secret modelling.
"So now states and territories can refuse for you to release a national figure? I've never heard of more absolute rubbish in my time in politics, honestly," Senator Gallagher said.
Professor Murphy rejected suggestions that state and territory health ministers asking for more federal funding indicated fears hospitals would not cope.
"It's not a cash grab, they all have aspirations of growing their hospital system," he said.
He said state health officials had assured the federal department health services would cope.
Deputy Chief Medical Officer Sonya Bennett, who has been working with states on the modelling, said at 80 per cent vaccination surge capacity was not stressed.
While some regular health system functions could face pressure as the nation lives with COVID, Dr Bennett was reassured about the impact introducing low-level social measures could have.
Australian Associated Press