Two of the parties in the North's power-sharing Government are poised to vote against a hard-hitting Budget that follows £4bn in cuts from London.
The Ulster Unionist Party (UUP) and the nationalist SDLP, junior partners in the Executive dominated by the DUP and Sinn Féin, have said they will oppose the plan.
DUP Finance Minister Sammy Wilson opened a marathon seven-hour debate at Stormont by accusing the smaller parties of electioneering on the issue ahead of the May 5 Assembly elections.
The budget, largely drawn up by the DUP and Sinn Féin, seeks to offset the cuts by identifying more than a billion in revenue-raising ideas, but opponents have claimed the financial blueprint does not stand up to scrutiny.
Mr Wilson told the Assembly: "I have said many times that I would welcome all new ideas but sadly nothing realistic has emerged from my loudest critics.
"Any ideas that have emerged are often contradictory or display a profound degree of ignorance of the public expenditure regime that the devolved administrations have to operate within.
"So, unlike my critics, I didn't have the luxury of being able to construct a budget that wasn't earthed in reality."
The UUP holds two ministerial seats in the Assembly Executive, while the SDLP holds one.
And while the parties' ministers have already opposed the budget plan, they have said they will not walk out of government.
Final budget plans earmarked another £432m (€503.3m) for key public services in the North.
The Ulster Unionists and SDLP have opposed reallocations which will see health and education handed extra money because they believed the review does not go far enough.
Mr Wilson accused them of cynical politicking ahead of May's Assembly elections as splits in the all-party ministerial Executive widened.
Health Minister Michael McGimpsey has said the health service could go bankrupt if more money is not allocated. He had been pressing for an extra £200m (€233m) for every year of the four-year Budget.
Mr Wilson said: "It does seem rather incredible that the Health Minister has talked about insolvency and Chapter 11, although what the relevance of a US commercial bankruptcy code is I don't know. I am only concerned about a public service here in Northern Ireland."
The final Budget allocated a further £189m (€220.2m) additional spending to health.
Mr Wilson added: "The health minister has decided to make health provision a political football within the context of this budget.
"He talks repeatedly about the decline in service provision but fails to make the connection with his four-year tenure."
Ulster Unionist finance spokesman David McNarry tabled an amendment which sought to channel extra money towards health and criticised the current plans.
"They are not proposals for a Budget in a real sense but proposals based entirely on statements of intent which are in themselves based on wing-and-prayer assumptions, assumptions which cannot be stood over, which are not proven to be deliverable and have been effectively cut to ribbons by a growing list of notable economists and other bodies such as Age NI, the Royal College of Nurses, the Construction Employers' Federation, the CBI and NIPSA."
The Strangford MLA said there should have been a programme for government to confirm agreed priorities.
"So this is budgeting on the hoof, it is very untidy, it is inevitable that the outcome of the way this dysfunctional Executive does its business proves to this Assembly it is not working for the people of Northern Ireland and therefore whilst it is very disappointing, it is not surprising to find last Friday in the finance minister's statement a comprehensive live list detailing DUP/Sinn Féin cuts," he said.
"They are not for us to support. We in the UUP are concerned most of all with delivering the people's priorities and chief among those priorities is spending on health.
"Therefore, ownership of the cuts belongs only to the DUP and Sinn Féin parties in this house."
SDLP leader Margaret Ritchie said: "The DUP/Sinn Féin authors of this budget have taken a completely defeatist approach when it comes to cuts.
"They tell us that London has handed us a settlement, complete with £4bn (€4.65bn) in cuts, and there is nothing we can do to mitigate it, even over four whole years.
"I am sorry but that is not good enough for the SDLP. Our people deserve better."
She said the Budget was "lazy and unimaginative" and accused the DUP of "ostrich economics".
She denied that her party was opposing the budget for political reasons and said the SDLP had made constructive Budget proposals.
Ms Ritchie said there was no programme for government and said it should have been drafted before spending plans were drawn up.
The SDLP leader said the budget could have done more to encourage job creation and agreed with the UUP that health was being given insufficient funding.
She made a swipe at Sinn Féin's political strategy in the Republic, where its opposition to major cuts has formed part of its recent election success.
"The position of Sinn Féin is utterly unsustainable," she said.
"The Sinn Féin socialists have waved through £4bn (€4.65bn) of cuts in Northern Ireland without so much as a whimper, while pretending there is an alternative to the inevitable cuts in the South.
"The position of the party can be summarised as: in the North, green Tory; in the South, different story."
Her comments came as the strengthened Sinn Féin team of 14 Dáil (parliament) representatives was taking its seats in Dublin at the start of the new term following the recent General Election.
At Stormont, Sinn Féin's Daithi McKay said the SDLP had tabled proposals for reforming the Northern Ireland budget, without explaining how it would pay for the changes.
His party colleague, Mitchel McLaughlin, said the SDLP had stood in the Westminster General Election on a promise to fight the cuts in the House of Commons, but had failed.
He also told the Assembly: "The Budget Review Group exists, it comprises ministers of every party that is represented on the Executive.
"Unless people can actually argue credibly that they have produced proposals that would have given more financial resource, that would have given more economic muscle, that would have protected frontline services, we have been asked to believe, not just in this House, but the public are being asked to believe that the Executive turned their backs on those proposals because the SDLP proposed it, because the Unionist Party proposed it.
"I think the record of the contribution, if that's the correct word, of the SDLP and the Unionist Party to the Budget Review Group process will demonstrate that they have not added one pound note to the budget proposals that are in front of us today.
"They have sought to divide where others have sought to develop a collective approach."
He said it was a huge task to plug the £4bn (€4.65bn) in cuts to the North's block grant from London, but he said the Budget provided a "credible beginning" to what would be a long-term task.
The Alliance Party's Stephen Farry said the structures of government at the Assembly were "far from perfect".
He added: "But we have to deal with the institutions as we find them today.
"We are determined to make the Executive work better and to work more collectively.
"That is our position and I think that is the position of the vast majority of the people of Northern Ireland.
"It is a shame, a crying shame, that other parties have not sought to be similarly constructive. I believe that the positions of the UUP ad SDLP are utterly unsustainable.
"They are the parties that perhaps claim the most about the Executive being dysfunctional, but today they stand exposed as the parties that are making the Executive most dysfunctional."