The Finance Minister has refused to give a commitment that the new National Children's Hospital will not tip over the €2 billion mark.
However, Paschal Donohoe has told the Dáil that the Government has "learned lessons" from the hospital, which is already running €455m over budget, and a new assurance process will be established next year for large scale public projects.
It has been revealed that the contractor building the hospital has submitted further claims relating to additional spending, however, these claims have yet to be assessed and settled.
Sinn Féin's Pearse Doherty asked Mr Donohoe to give a guarantee that the final hospital price would not increase more and end up costing the taxpayer over €2bn.
But Mr Donohoe told the Dáil: "I'm not going to give any further indication in relation to what the final cost will be until I have clear information available but I've always said there is potential for that cost of change given all that we have gone through with relation to these projects."
But he said that the Government will do all they can to ensure that good value for the taxpayer is delivered.
Mr Donohoe added that his Department will now be working to put in place an assurance process for projects above €100m.
Referring to both the children's hospital and the National Broadband Plan, Mr Doherty claimed taxpayers who are "fathers and mothers who are working every hour they can get" expect the government to ensure that all revenue that is collected is spent appropriately.
"These two projects the overrun equates €3.5 billion. There is no doubt that if these projects were managed properly, that €3.5 billion euro could go into the areas which are starved from investment."
Fine Gael TD Bernard Durkan asked the Minister if the Government are simply using very old figures or if public capital projects are reassessed on a regular basis.
Mr Donohoe said it can take a considerable amount of time between agreeing a project and going to tender and in the meantime the economy and the rate of inflation may have changed.
"The length of time between project is agreed and then going to tender can be many many years, that it does happen, that a project ends up being evaluated against the figure, that was shared in good faith but the economy has changed, which means the tendering process gives another price and that is the issue that we have to grapple with," he told the Dáil.