The onus is on the Northern Ireland Executive over the rebuilding of Casement Park, Secretary of State Hilary Benn has said.
Mr Benn set out that either more funding is found for the long-delayed GAA stadium or the current plans are scaled back.
He was speaking to the Northern Ireland Affairs Committee on Monday after the UK Government pledged £50 million earlier this month for the project.
There are also pledges of £62.5 million from Stormont, £43 million from the Irish Government and £15 million from the GAA.
However, the current plan for a 34,000-capacity stadium is still short of cash with a reported estimate of £260 million, while just over £170 million is currently available.
Stormont ministers committed £62.5 million to Casement in 2011 as part of a strategy to revamp it along with football’s Windsor Park and the rugby ground at Ravenhill.
While the two other Belfast-based projects went ahead, the redevelopment of Casement was delayed for several years because of legal challenges by local residents.
The estimated cost spiralled in the interim.
Mr Benn put to MPs that there are two ways to proceed.
“One is to find more resources from elsewhere and I think the onus is back now on the (Stormont) Executive whose project this is, dating from 2011,” he said.
“Either you find more money to get it towards the current assessed cost or the nature of the design is scaled back to fit the funds that are available.
“Those are broadly the two choices, or some meeting point in between, but I do think that it gives quite an impetus to the project.
“The Executive has wanted to do this since 2011, there are particular reasons to do with planning which have made it difficult, and that’s been significantly responsible for delay.”
Mr Benn also cautioned that the current planning permission is due to expire next summer and said to have to reapply for planning permission would cause further delay.
He added: “Windsor Park has been done, Ravenhill has been done, but Casement Park has not.
“I want the people of Northern Ireland to be able to enjoy those three great sporting traditions in three stadia. That’s why the Government’s made the contribution.”
