Public-sector pay demands, help for displaced Ukrainians and rising inflation are said to have put "enormous strain" on Scotland's budget.
The BBC says Deputy First Minister John Swinney told MSPs yesterday that around £500million in cuts had been identified to ease the pressure.
He said a lack of borrowing and an inability to vary Income Tax rates outside the normal budgetary timetable had left him with "no other choice".
But Conservative MSP Miles Briggs said cash for another referendum appeared intact.
In a statement in the Scottish Parliament, Mr Swinney set out changes, including:
- A reduction of £53million in the budget for employability schemes.
- Using funding of £56million generated by the ScotWind clearing process – cash which will be reinstated in future years and used, as planned, to invest in the Just Transition.
- £33million deferral of ring-fenced agriculture funds, to be returned in future years.
- A reduction of £37million in the budget for concessionary fares.
Mr Swinney said the decisions were not ones the government would have wanted to make.
But he added that it was important that the scale of the challenge was clearly understood, particularly by anyone negotiating further pay deals.
He told MSPs: "These individual savings are small amounts in themselves, but together they add up to a significant reduction in expenditure, enabling that money to be invested in addressing the financial challenges we face."
Paul White, director of the Confederation of Passenger Transport (CPT) Scotland - a trade association representing bus and coach companies - raised concerns about the £37million reduction in the budget for concessionary fares.
He said: "The concessionary budget is evidence-based and calculated to fairly reimburse bus operators for carrying concessionary passengers.
"Any budget cut that compromises that commitment undermines the principles of the scheme.
"If there is a possible £37million saving within this year's concessions budget, I would ask why that hasn't been used to insulate bus passengers from the cost-of-living crisis by continuing the enhanced bus network support grant beyond October."
After the Deputy First Minister detailed cuts yesterday, Tory MSP Mr Briggs said it was "astonishing" that the cash earmarked for an independence referendum had "somehow escaped John Swinney's axe".