The SDLP leader made the claim in the British House of Commons this week during oral questions to the Secretary of State for the north Brandon Lewis.
"The Secretary of State will know that there is £300 million in a bank account in Stormont that cannot be spent because the DUP walked out of the Executive. He will also know that there are families in Northern Ireland who cannot heat their homes or feed their children.
"If the Executive cannot meet after the election, will he commit to working with me to get that money into people’s pockets as soon as possible?" asked Mr. Eastwood.
In response Mr. Lewis claimed the DUP's boycott of the Executive was not the reason the £300m was off limits.
"I agree in part with the hon. Gentleman —it does not happen all that often at the Dispatch Box—because I want to see that money being spent for the benefit of people in Northern Ireland, but I disagree with his analysis of why it is not being spent.
"That is money from last year’s budget, and for a couple of years running now the current Department of Finance in Northern Ireland has consistently underspent. The Executive needs to find ways of ensuring that the money is properly spent," he said.
Mr. Lewis went on to explain how Brexit, the British government's Withdrawal Agreement and its Protocol were causing problems for the north.
"I have to say that the hon. Gentleman has also identified a real issue with the Northern Ireland protocol, because the UK has put substantial extra money into the pockets of people across the UK through VAT and fuel duty cuts, but we cannot do some of that directly in Northern Ireland because of the protocol.
"We have therefore made that money available to the Executive and I want to see it get to the people of Northern Ireland.," he said.