The opening of the national children's hospital's two satellite centres has been pushed back as it is emerged the cost of the long-delayed project has spiralled to nearly €1.4bn - up from €1bn in just 18 months.
The satellite centre in Connolly Hospital, which was due to be ready at the end of 2018, will now not open until next summer.
And the centre in Tallaght Hospital will not receive young patients until 2020, even though it was earmarked for early next year.
The opening of the main hospital, which is being built on the campus of St James's Hospital, is also being delayed until 2022.
The latest setbacks come after it was revealed Health Minister Simon Harris will tell the Cabinet the €1bn cost, set less than two years go, has risen to almost €1.4bn.
BAM Ireland, one of the State's largest building contractors was chosen to build the hospital in 2017 for €1bn, a massive jump from its €650m price tag when planning permission was sought.
Labour TD Alan Kelly accused Mr Harris of losing control of the hospital's budget. He said he will be asking the Dáil's spending watchdog, the Public Accounts Committee (PAC), to examine the costs to date to understand how, in two years, the projected cost has more than doubled from €650m to as much as an estimated €1.4bn.
He raised concern the rising costs will put other capital projects in the health service risk.
PAC chairman Seán Fleming and committee member Catherine Murphy are also to press for answers.
Fianna Fáil spokesman on health Stephen Donnelly said: "It's just over 18 months since the minister told us that he expected the cost of the hospital to be approximately €1bn and perhaps more importantly, that it would be delivered on time. We need to know what that is.
"A 40pc increase in costs since spring 2017 cannot be brushed aside. We need to know that the taxpayers and ultimately the service users are getting the best value for their money."
Mr Harris rejected the claim the costs are out of control. He said it was "no surprise" that after a recession there has been "hyperinflation" in construction costs.
"We do need to remember what we're doing here. After decades of talking about building a hospital that work is now under way and I'm very proud of that."
He rejected suggestions that the rising costs were due to the way the project is being run, saying the people overseeing it are "hugely competent" and he has "every confidence" in their ability.
Experts say construction inflation is only one factor in pushing up the cost and other factors like design are involved.
Building costs generally have increased by around 7.4pc this year, fuelled by labour shortages and other pressures.
The system of traditional procurement which rewards the bidder who offers the lowest price was not used in the case of the hospital.
A two-stage process is in place and the second is now being finalised and agreed.
It was claimed that "considerable progress has been made on the construction project this year". Enabling works on the main hospital site are complete and substructure works on the main site "also now nearing completion".