The Finance Minister says he will have no option but to publish a list of cuts from every department to meet the potential £1bn cost of failing to introduce welfare reforms in Northern Ireland.
In response to to questions from Sinn Fein at Stormont yesterday, the DUP's Simon Hamilton said the impact of cuts will be borne by "very vulnerable people".
He told MLAs that "we will sure as hell feel the impact of £1bn being taken out of our ability to spend over the next five years".
Sinn Fein claims the changes would mean £450m will come out of the local economy.
But Mr Hamilton argued that spending on welfare would still continue to rise – but it would be much less than expected.
The £1bn is the amount we would lose over five years if changes to welfare legislation are not mirrored in Northern Ireland.
When Fra McCann said he did not recognise these figures, Mr Hamilton flashed back that the Sinn Fein MLA "will start to recognise them when we see cuts to every single department".
"I will have no option but to bring forward a paper to Executive colleagues outlining how I think we should best reduce our expenditure across all departments by £105m next year," he added.
The DUP has been promoting a package, as revealed in the Belfast Telegraph yesterday, it says was agreed in talks Sinn Fein last June.
But Sinn Fein said that only the party's all-Ireland leadership could agree to something like this.
"Claims that Sinn Fein reneged on a deal are totally untrue. At no time has Sinn Fein agreed to any finalised package around the Welfare Bill," said Alex Maskey.
"The DUP would have signed up to the Bill in its original form except we in Sinn Fein and others argued that changes had to be made. We have reached potential agreement on a range of issues, but there is more to be done."
Stewart Dickson of Alliance agreed that the DUP would have accepted the Government's welfare reform package without any concessions if other parties hadn't pressed it. He also accused Sinn Fein of pulling back on movement because of May's elections.
"Sinn Fein are seen to be getting a bit of a track record on things like this where they say 'no, no, no' in public, but in the background they say 'OK'."
Dolores Kelly, who speaks for the SDLP on the issue, called on Deputy First Minister Martin McGuinness to go to the UK Government and ask for a better deal.
Michael Copeland of the UUP said: "It is a scandal the DUP and Sinn Fein, through their wrangling on this issue, have exposed the Northern Ireland Executive, and public services provided by it, to monthly financial penalties."
The coalition Government is replacing many existing benefits with a Universal Credit. The amount of money we get to spend on welfare here is proportionate to England, so if politicians here resist copying those changes the shortfall must come from Northern Ireland's own budget. Yesterday the Belfast Telegraph revealed that a compromise deal had been tabled which would cushion some of the financial impact but still cost us £28m-43m a year. The DUP accuses Sinn Fein of agreeing to this but then reneging.