Prime Minister Tony Abbott has denied ordering bosses at the nation's peak science organisation to cut up to 20 per cent of its workforce.
A political storm broke on Friday after The Canberra Times revealed that up to 1400 scientists and researchers at the CSIRO would lose their jobs under the terms of a government-imposed ban on the public service renewing temporary contracts.
Labor and the Greens accused the Coalition of another attack on science while the organisation's staff said it would damage life-saving research projects.
But Mr Abbott said the CSIRO cuts were a matter for the organisation's management.
"We haven't made any cutbacks to the CSIRO," he said. "The management of the CSIRO and the employment of staff inside the CSIRO and the management of contractors for the CSIRO is a matter for the CSIRO itself."
Senior figures in the CSIRO gave media interviews on Friday suggesting the reports of up to 1400 jobs on the line were exaggerated and the real figure was closer to 300.
Labor parliamentary secretary Amanda Rishworth said the cuts would hurt the nation.
"What we are seeing here is a theme from a government that doesn't want to listen to scientists," Ms Rishworth said.
"They didn't have a science minister when they appointed their ministry and now what we are seeing is huge cuts to our capacity as a nation to do research, to investigate programs that affect our nation."
Acting Greens leader Adam Bandt accused Mr Abbott of trying to mislead the public about responsibility to the cuts.
"Tony Abbott is misleading the public on the CSIRO job cuts," Mr Bandt said.
"The CSIRO job cuts are a direct result of Tony Abbott's decision to cut back the public service and a government directive to the CSIRO to implement these cutbacks was made clear in a CSIRO management memo to staff.''
The CSIRO Staff Association said on Thursday that the cuts would have an impact on Australia's ability to undertake cutting-edge science that improved the everyday lives of millions of Australians.
Association secretary Sam Popovski said that the job losses would hit a range of life-saving research and science that improved the everyday lives of millions of Australians.
"Recent examples of CSIRO innovation are as diverse as Australia itself - from new software to more accurately predict the spread of bushfires to a new process enabling three-dimensional printing of customised shoes for racehorses," Dr Popovski said.
"Our smartphones are powered by Wi-Fi technology pioneered by CSIRO.
"Even our plastic banknotes - that's polymer currency - another CSIRO innovation.
"How can CSIRO develop the next generation of Australian innovation if their capacity to conduct research and development continues to be cut?"
CSIRO staff leaders confronted their bosses on Thursday, demanding answers on the fate of more than 1400 "non-ongoing" workers at the organisation.
Staff were told last week of the freeze, which will hit the organisation's 11 research divisions and 11 national research flagships, critical support and frontline scientists.
The staff freeze threatened to paralyse some of the organisation's premier research projects, they were told.