Arlene Foster has described any suggestion DUP support for the Brexit withdrawal agreement could be bought with further major investment pledges for Northern Ireland as "offensive".
At Stormont for talks with British Prime Minister Theresa May, the DUP leader was asked at a press conference whether another "bribe" would win her party round - a reference to the £1bn (€1.13bn) secured by the DUP as part of its confidence and supply deal with Mrs May's Tories at Westminster.
"We didn't take a bribe in the first place - the confidence and supply agreement was for all of the people of Northern Ireland," she said.
"Some of that money has already been delivered. We look forward to the rest of that money being delivered for all of the people of Northern Ireland.
"It is very offensive to raise this in terms of money. We are talking about the constitutional and economic long-term future of Northern Ireland - so the answer is no."
Ms Foster suggested opposition to the deal at Westminster was "coalescing" around the Border backstop proposal.
"So if she ditches the backstop there is every reason to believe that this withdrawal agreement could go through," she added.
All five of the main Stormont parties held talks with Mrs May at Stormont House yesterday.