Chancellor Gordon Brown's financial peace package offer may be increased, Sinn Fein's Martin McGuinness has said.
The two politicians are continuing their negotiations
Mr McGuinness said he and first minister designate Ian Paisley could persuade Mr Brown to provide more financial aid for the new assembly.
Mr Paisley warned the creation of the executive could not be taken for granted "if the government failed to provide an adequate peace dividend".
Mr McGuinness, deputy first minister designate, said talks were continuing.
"I was very interested in some remarks made over the weekend by Peter Hain where he conceded that the debate on this issue was far from finished and clearly indicating Gordan Brown has not reached his bottom line position," he said.
"What we have to do is continue with the negotations and continue battling for people.
"Ian Paisley and I will battle together and we will make a very strong, powerful argument to the British government."
The DUP leader and Mr McGuinness are due to take a pledge of office as Stormont's first minister and deputy first minister on 8 May.
The two met Mr Brown last weekto discuss the financial package.
However, Mr Paisley said he was disappointed with the negotiations and that Mr Brown should not take the local parties for granted.
"We shouldn't have been put into this position," he said.
"All we have to say is, have your little pantomime on Tuesday, but we'll not be there.
"I want them to get that message. I want them to get the message that this is so serious that we can't possibly do justice to our country if we don't get this."
He said further talks were planned with the chancellor.
Devolution is due to return to Northern Ireland next Tuesday, following an agreement by the DUP and Sinn Fein to share power.
Prime Ministers Tony Blair and Bertie Ahern will be present to witness the restoration of the executive.