A potential £200 million a year bill for failing to implement welfare reforms in Northern Ireland is a price the region cannot afford to pay, the Finance Minster has warned.
Simon Hamilton said it had become "critically important" to legislate on the measures already introduced elsewhere in the UK as quickly as possible.
The proposals' passage through the Assembly hit the buffers earlier this year, with MLAs unable to reach consensus.
Mr Hamilton, outlining potential pressures on Stormont spending in the coming years, said the cost of not introducing welfare reform would hit the most vulnerable in society.
The Treasury has cautioned that Northern Ireland's block grant will be adjusted in line with the estimated cost associated with the region not implementing the measures.
Mr Hamilton said that was currently running at £5-6 million a month, with the annual bill set to be around £60 million.
"The worrying thing is that that bill is likely to rise to £200 million by 2017/18," he told the Assembly.
The proposed changes to the welfare system have been the cause of intense political debate in Northern Ireland, in particular the controversial so-called "bedroom tax".
The measure targets benefit recipients who are not deemed to be utilising all the bedrooms in their property.
If the changes are ultimately adopted in Northern Ireland, around 32,650 (52%) of working-age housing benefit claimants in the social housing sector are set to receive less money.
Opponents of the proposal insist the make-up of the social housing stock in Northern Ireland would mean many of those impacted would not be able to downsize to smaller properties. They also claim it would cost more to administer the change than the money it is designed to save.
Sinn Fein and the SDLP have voiced vehement objections to the "bedroom tax" and have threatened to support a petition of concern mechanism that would effective veto the proposals.
DUP Social Development Minister Nelson McCausland, who has also voiced concerns over elements of the bill, has been attempting to formulate Northern Ireland-specific alterations to the legislation that would still enable the legislation to be introduced without breaking the so-called "parity" principle on costing.
But as yet there is no sign of a resolution to the political impasse.
Mr Hamilton stressed to MLAs the need for resolution.
"Two hundred million pounds taken out of budget to pay for something because we haven't legislated is a price we cannot afford," he said.
"We need to move forward on this. I know that is something the minister for social development is unanimous with me on and is seeking approval to legislate in respect of welfare reform so that those very punitive penalties that I am speaking about don't actually materialise and don't start to the hit the very vulnerable people in Northern Ireland, who some who oppose welfare reform think they are helping."