Reports that Sue Gray has caused division in the UK government over support for Casement Park are “complete nonsense”, the British prime minister has said.
The derelict west Belfast ground has been earmarked to host five matches in Euro 2028, being jointly hosted by the UK and Ireland.
However, the funding required to rebuild the stadium in time for the showpiece football tournament is not in place, prompting concerns that the delays will see Belfast missing out.
There has also been mounting speculation that the long-delayed redevelopment of the GAA stadium would not be completed in time for the Euros.
It has been reported that Ms Gray has expressed support for financing the £300 million project, with the Downing Street chief of staff being accused of subverting British cabinet ministers in the talks.
DUP MP Sammy Wilson is among those who have raised concerns over the alleged role of Ms Gray in the negotiations.
Asked whether her involvement had caused divisions at Cabinet, Mr Starmer told reporters on Monday: “That’s complete nonsense, I hope that’s clear enough.”
Mr Starmer said “obvious issues” around timing and the cost of developing the stadium are being considered carefully.
“The decision is a political decision. The key challenges at the moment, I think, are well known, particularly in Northern Ireland, which is the timing in relation to the Euros and the cost.”
Speaking to reporters during a visit to Belfast, he said: “Obviously there’s a joint venture, the UK and Ireland together in relation to the Euros.
“We want football played everywhere in support of those Euros. Casement Park, obviously, is important in that respect.”
He added: “In due course, we’ll be able to say more.”
Costs for the long-delayed Casement project have spiralled, with reports suggesting the projected costs have soared beyond £300 million.
In 2011, the Stormont executive committed £62.5 million to the project.
Earlier this year, the GAA sporting body said it will contribute £15 million.
The Irish Government has offered roughly £42 million towards the project and indicated it may be open to spending more.