The DUP will not agree to further cuts to 'frontline services' to provide more money for welfare reform, the First Minister has insisted.
But Peter Robinson indicated there could be flexibilities within plans being brought forward by his party colleague, Social Development Minister Mervyn Storey, to resolve the new impasse threatening Stormont.
The DUP leader also warned the next Treasury fine over the Executive's failure to agree the welfare changes would mean cuts of £2m a week being enforced next year.
But he said he believed agreement could still be reached.
Sinn Fein withdrew support for welfare reform legislation two weeks ago. If the DUP and Sinn Fein can reach another deal, there is speculation the Assembly could be asked to sit for an extra day before the Easter recess.
"If we do not reach agreement, the Executive will still have to confront the challenges of how people in Northern Ireland will be paid their social security and tax credit payments in the future, as the Department for Work and Pensions and HM Revenue and Customs will be closing their legacy IT systems, which we are presently using," he warned.