The DUP has accused Sinn Fein of holding Northern Ireland to ransom after Stormont departments were asked to make plans for cuts to their budgets.
The Department of Finance has begun a 'scoping exercise' to assess how looming spending cuts could be absorbed in the public sector.
It has asked the majority of Stormont departments to plan for scenarios in which there would be a 4%, 8% and 12% reduction in their resource budgets for the next two financial years.
The Department of Health has been exempted, as no health service cuts are envisaged.
DUP MLA Christopher Stalford said: "This scoping exercise is being carried out in the absence of any input from those elected by the people of Northern Ireland.
"The DUP would have formed an Executive in March. Sinn Fein is blocking devolution.
"Health, education and investment decisions are being hampered by budget uncertainty.
"They should stop holding Northern Ireland to ransom."
Mr Stalford said he wanted to see the extra funding his party secured in its £1 billion deal with the Tories "benefiting the people of Northern Ireland as soon as possible".
Ulster Unionist leader Robin Swann expressed concern about the lack of local political input into the scoping exercise.
"These are decisions which were going to have to be made by Executive ministers," he said.
"It's an abdication of political responsibility that this is happening without ministers in place. The country is being held to ransom by those who place their ideology above the wellbeing of our people."
SDLP MLA Claire Hanna said the scoping exercise showed the "severe austerity" that was coming and predicted it would be worse without functioning political institutions at Stormont.
"Virtually every day now we have civil servants making decisions on budget cuts, only to be criticised by politicians before they're reversed," she said.
"The pressure in the system is becoming unbearable.
"We can't have government by Press release - without strategic direction, with priorities, a serious financial crisis will lead to unavertable and deep austerity.
"Our schools, infrastructure and economy can't take that kind of pressure. Power-sharing must be restored."
Alliance deputy leader Stephen Farry said the development illustrated "the increasingly perilous state of our public finances and the ever-tightening public expenditure framework".
He added: "Every time departments are force to retrench, our public services are further damaged and our ability to transform our economy is undermined.
"Even protection for the health service is limited in the context of the scale of healthcare inflation.
"There is an urgent need for a much more strategic approach to be taken to public finances, including greater collaborative working and addressing the waste that is involved in providing parallel services in a divided society."
Sinn Fein was contacted for a comment but none was forthcoming.
The scoping exercise will not result in any final spending decisions in the short-term due to the absence of a power-sharing Executive.
The information will, however, be used to inform the formulation of future budgets either by a Stormont Executive or direct rule ministers.
As a result of decisions already taken by the Treasury, Stormont's resource budget will flat-line at around £10bn over the next two years - which means a reduction in real terms when inflation is factored in.
Officials are working out how to free up funds from within the current allocation to address pressures that will no doubt emerge in the 2018/19 and 2019/20 financial years.
The individual departments will now engage with their arm's-length bodies to establish what impact the three scenarios would have on service delivery.
In terms of money for capital projects, Northern Ireland will receive more from the Treasury in the coming years.
The budget is around £1bn in this financial year, due to rise to £1.095bn in 2018/19, £1.160bn in 2019/20 and £1.230bn in 2020/21.