Budget cuts due to the welfare impasse will have a dramatic impact on public services, Northern Ireland finance minister Arlene Foster warned.
Benefits, efforts to attract investment and roads work would be badly affected and the Democratic Unionist said the intervention of Northern Ireland Secretary Theresa Villiers may be the only way forward.
A Sinn Fein/SDLP block on introducing the Government's welfare reforms in Northern Ireland has put the Stormont House deal, and the £350 million funding boost that comes with it, on hold.
Ms Foster said: "If this budget bill and Stormont House Agreement does not go ahead then I have listened around the Executive table to all of my colleagues indicating the very dramatic impact it will have on public services."
That was not confined to benefits but included government jobs creation body Invest NI and the Department for Regional Development's work on roads, the minister told Stormont's Finance and Personnel Committee.
"Each individual department has set out very clearly what will happen if they don't have access to accruing resources as a result of the budget bill going ahead.
"It is a very critical time."
She added: "If the Secretary of State has to intervene it will be very regrettable but it may be only way forward."
She said a budget bill tabled at the Assembly earlier this week was not based upon fantasy but predicated upon welfare reform going ahead.
Finance committee chairman Daithi McKay, Sinn Fein, said more cuts were expected to be announced by the Chancellor next month.
He told the minister: "These announcements have been met with outrage by your counterparts in Cardiff and in Edinburgh, in other devolved administrations, but the (Finance and Personnel) Department here, the response has been more muted.
"Is it fair to say the Department is taking a softer approach?"
Ms Foster said she is to meet ministers in Wales and Scotland. She meets chief secretary to the Treasury Greg Hands later.
"I would hope that we will have a good relationship and we will be able to work together.
"I do hope as well that they will give us more respect as devolved administrations and will work with us in that regard."
Chancellor George Osborne has condemned a budget plan that commits the Stormont Executive to a £600 million overspend as "unacceptable".
The finance committee later agreed to allow Ms Foster to rush her new budget bill through the Assembly.
Unless welfare reform is resolved the departments are due to run out of money later this year but the legislation defers for now the threat of a civil servant assuming responsibility for public finances.