The executive will meet on Tuesday morning to discuss the government’s offer of money to implement the Stormont deal.
Finance Minister Conor Murphy said on Monday night that what had been proposed “falls way short” of what the political parties expected.
That followed a meeting between the Stormont parties and Secretary of State Julian Smith.
The financial offer was made by the government during the meeting.
The new finance minister said the government’s proposal did not go far enough.
“We have to analyse the verbal figures that were given to us tonight by the secretary of state, but my initial read of them is they fall way short and I wouldn’t tend to accept that,” he said.
“They can’t come today [Monday] and congratulate us for living up to our commitments and then not live up to their own.”
Earlier, the prime minister said the government had made “huge commitments” as part of the deal.
But he did not state how much money would be provided to support the deal, saying it was not about money but leadership.
On Tuesday, the 10 new executive ministers will face their first challenge, finalising the amount of money they are getting to sort out issues stalled over the past three years.
The executive has a raft of issues it wants to tackle and if it does not get the sum it was expecting, it may have to review its priorities.
The assembly will also sit on Tuesday as MLAs meet to appoint the new chairs of Stormont’s nine scrutiny committees.