Finance Minister Mathias Cormann has warned that if the government's proposed budget spending cuts are not passed, "the only alternative to balance the books is to increase taxes".
And ahead of Parliament resuming on Tuesday, Education Minister Christopher Pyne has suggested universities could face a "worst case" scenario of funding cuts without sector reforms if the Senate does not pass his proposed higher education reforms.
The comments from both cabinet ministers are designed to step up pressure on Labor, the Greens and the crossbench to back the government's contentious budget savings and come ahead of Monday's cabinet meeting, which will focus on budget strategy.
Senator Cormann told the ABC's Insiders program there was "no rush to deal with specific structural reforms", such as the university funding changes, because many of these changes did not begin until July 2015 or later.
"We have laid out our plan to reduce the unsustainable spending growth trajectory Labor left behind," he said.
"Essentially, if we stay on a spending growth trajectory that takes us to 26.5 per cent of the share of GDP when tax revenue on average over the last 20 years was 22.4 per cent of the GDP and [if] you don't want to balance the books by reducing spending, the only alternative to balance the books is to increase taxes."
In a challenge to the Opposition Leader, Senator Cormann said: "What is Bill Shorten's plan? Is he planning to increase taxes in order to make up for Labor's unsustainable spending growth trajectory?
"Our plan is in the budget. We delivered a budget in May which presents our plan to put the budget back on a believable path back to surplus and we are now working in an orderly and methodical fashion to implement that plan through the Parliament."
In an interview on the Ten Network's Bolt Report, Mr Pyne said months of talks with the Senate crossbench had led him to believe the "momentum is with the reforms" and that "I'm making great progress".
"I know it sounds probably like hype over reality, but I believe the momentum is with the reforms in government with the higher education. I believe most of them will pass."
Mr Pyne said that without reform, Australian universities would "slide into mediocrity" and that "rather than presiding over the slow decline of the manufacturing sector, I'll be presiding over the slow decline of the higher education sector.
"I don't want that to happen."
Mr Pyne said a Fairfax Media report that the federal government will examine slashing billions of dollars worth of research funding from universities if Parliament blocks its changes was "highly speculative" – but then effectively confirmed such a step could be taken as he declined three opportunities to rule it out.
"I don't know where it came from but I think the piece was suggesting that if the Commonwealth grant scheme doesn't cut, doesn't go ahead, the only area the government can reduce spending is in areas like research," he said.
"Well, that's not our plan. Our plan is to see our budget pass."
"The worst-case scenario is cuts without reform. And I think the university sector gets that."
The Education Minister criticised university student protesters – some of whom repeatedly tried and failed to burn an effigy of him last week – arguing the government simply wanted them to pay 50 per cent of their education costs. Students currently pay for 40 per cent of the cost of their course.
"We're hardly asking for the world," Mr Pyne said.
"They really don't have the kinds of problems that they are protesting about that deserve the burning of effigies. We're asking to pay 50 per cent of the cost of their education. We're not asking for their left kidney to be donated," he said.