Powers over benefits in Northern Ireland could be handed back to Westminster if no solution is reached over welfare reform, Peter Robinson has warned.
The First Minister spelt out his threat of taking the "nuclear option" if the stalemate between the DUP and Sinn Fein cannot be resolved.
"It would not be an unusual step if that were to occur, if we are not prepared here to face up to our responsibilities," he said.
"If people are not capable of governing and taking those difficult decisions, then that power should not be devolved."
The DUP blames Sinn Fein for blocking welfare reform, which republicans believe will drive more people into poverty.
Even though it would mean one of his own ministers, Nelson McCausland, losing control of a large part of his Department for Social Development, the DUP leader said he favoured Westminster holding the reins on welfare spending rather than them being in the hands of Stormont.
"I'll be honest with you, I am one of those who had not thought these powers should be devolved to us," Mr Robinson said.
He explained that this was because he preferred to "maintain parity" –meaning using the same system here that is used in the rest of the UK.
Another nuclear option could emerge if the Executive ends up unable to agree a budget next year as a result of fines the Treasury has begun to impose on Stormont for not implementing welfare reform.
Mr Robinson noted that if the Welfare Reform Bill was not implemented, Stormont faced budget cuts. And if departments overspent, that might mean further massive financial penalties.
The First Minister said the impasse had come to a head now after Chief Secretary to the Treasury Danny Alexander said Northern Ireland's block grant was going to be reduced with immediate effect if it did not move to the new benefits system in line with Britain.
Mr Robinson said this meant the people of Northern Ireland were now being asked to suffer as a result of the "bad behaviour" of Sinn Fein.
"There is no avoiding this now. And let us be clear, this is not a necessary crisis," Mr Robinson said in Newcastle, as he announced the Irish Open would be coming to Royal County Down.
He severely rebuked both SF and the SDLP for bandying about "mythical figures" that welare reforms would cost Northern Ireland's economy an estimated £450m in spending terms.
Westminster wresting back responsibility for social welfare –which would require passing legislation in the House of Commons – is thought to be a realistic prospect if the current impasse leads to benefits payouts being affected.
The First Minister made clear, however, that his "nuclear options" do not, at least in the forseeable future, include the DUP pulling out of the Executive. But as Mr Robinson upped the ante, Sinn Fein accused the DUP of a "huge blunder". Alex Maskey, chair of the Stormont committee overseeing welfare changes, said Mr Robinson had chosen to provide backing vocals to scaremongers in his party rather than real leadership.
"I think it is a shameful exploitation of some of our most vulnerable people and a huge blunder on the part of the DUP, who are only attempting to mask their failures both to stand up to the British Government and in terms of managing the health service," he said.