THE new projected cost of redeveloping Casement Park is £110 million.
The updated figure is £32.5m more than the west Belfast stadium plan's original budget of £77.5m – an increase of more than 40 per cent.
Stormont has already pledged £62.5m towards the project, but GAA chiefs want more public money to help plug the funding gap.
Civil servants say they cannot allocate more funding in the absence of a power-sharing government without ministerial approval.
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It comes almost 10 years since Ulster GAA first announced its plan to build a major new stadium at Casement Park, but the project has faced numerous problems and setbacks.
In 2014 planning approval for the original 38,000-capacity design was quashed in a legal challenge.
Revised plans for a 34,000-capacity ground were submitted to Stormont officials in the Department for Infrastructure (DfI) in February 2017 and are still under consideration.
The project has so far cost around £10.1m before construction work has even begun.
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Northern Ireland has not had a power-sharing government since the executive fell apart in early 2017.
There have been questions over what decisions can be made in the executive's absence following a major court ruling in May last year, when a judge said civil servants did not have the legal power to approve an incinerator planning application without ministers.
Last year, legislation was passed at Westminster in an attempt to give Stormont officials greater legal clarity on decision-making without local ministers.
Ulster GAA says DfI has said in correspondence it "may" be able to make a final decision on the Casement Park planning application.
Tom Daly, chairman of the Casement Park project board, said the prolonged planning process is "stalling the project's progress".
He said delays in some statutory bodies responding to planning officials about the Casement application has been a "cause of frustration within our project team and across the wider GAA community".
"Ulster GAA recognises and fully respects the required due diligence by the Department for Infrastructure (DfI) and all statutory consultees," he said.
"However, the prolonged nature of the planning process is stalling the project's progress and is also impacting its budgetary estimate which is now likely to be in the region of £110m.
"With every day of delay pushing out the earliest possible start on site for the project it is imperative that government departments discharge their responsibilities as expediently as possible to mitigate against increased costs."
He added: "Everyone at Ulster GAA would like to thank our members and our communities for their continued support throughout this process and we place on record our unambiguous commitment to ensure that Belfast will have a world class stadium for gaelic games to serve the needs of the GAA in Ulster, Antrim and throughout Ireland long into the future."
