The Minister for Health has told the Oireachtas Health Committee that he will not entertain any talk of pausing the new National Children's Hospital, or moving the location.

Simon Harris said the project had been paused enough times and the decision was made to proceed and building is under way.

Mr Harris said that the Government did not just decide to proceed with the project after the overruns became apparent, but it also ordered an external review.

He said it was one of the hardest decisions made by Government to proceed but it did so frustrated with the overrun.

He said the overrun was colossal at €450 million.

He said he first became aware of the scale of the overrun on 9 November last and the Government was informed on 18 December.

Mr Harris said that the PWC review will be published and there may need to be changes in the way the project is managed and overseen.

He asked that people not predetermine the issue and await the PWC report.

The Minister said there will have to be accountability as something went majorly wrong.

Michael Harty, Committee chairperson, said that the complexity of the project was at the heart of some of the overrun but also the two stage tender process did not properly determine the cost of the project.

Stephen Donnelly, Fianna Fáil, described it as an absolute scandal.

The Secretary General of the Department of Health Jim Breslin described the situation with the new hospitals as a mess, but defended the project going ahead.

Mr Breslin told the committee that to re-submit a design and re-apply for planning would have added three years to the project, and could have ended up costing more, given inflation trends.

"The likelihood is you would have ended up with an inferior project, an inferior hospital, at something approaching the same costs we are presented with today...you would have deferred the building of this project for a generation," Mr Breslin said, rejecting the suggestions that the project could have been scaled back. 

"We would have ended up in a bigger mess", Mr Breslin told the committee.

"I absolutely agree this is a mess. And I am totally unhappy with the situation we're in... the situation we are in now is absolutely invidious, but we are going to build a hospital that has been required in this country for 30 years," Mr Breslin added.

He also rejected the cost was associated with the site.

Speaking in the Dáil this afternoon, the Taoiseach promised to provide clarity as soon as he can on what projects might be effected as a result of cost overruns at the National Children's Hospital.

Leo Varadkar said he accepted that questions around where the money will come from is causing anxiety.

He said €100m will have to be found from other capital budgets this year and €450m between now and 2021, but that is likely to delay projects by "weeks or months" rather than cause their cancellation outright.

He said other savings might arise from projects being deferred, not because of any Government decision, but because of planning delays or judicial reviews.

"I do realise it is causing anxiety and that a lot of people feel that the particular project that they are particularly interested in is now being held up as a consequence of over-runs at the national children's hospital. That is absolutely not the case. So we will try to clarify that as soon as we can," he told the Dáil.

He was responding to questions from the opposition who strongly critical of how the project was managed. 

The Labour Party leader, Brendan Howlin, asked what projects will not be advanced this year to meet the requirements of the children's hospital.

"There is great anxiety about every project right now, wondering where the axe might fall," the Wexford TD said.

The Fianna Fáil leader, Micheál Martin, accused the Taoiseach of repeatedly trying to downplay the impact of the children's hospital overrun on other projects.

"You are desperate not to admit the impact of what has happened on the many projects that you have launched," he said.

Mr Martin asked if the dramatic increase in construction inflation that is being applied to the children's hospital will apply to capital projects across the board.

"The issue is whether you are willing to be honest with the public and publish the exact impact on the National Development Plan of both this overspend and the rising costs which are applied to all other projects across the NDP."

People Before Profit TD, Richard Boyd Barrett said Fine Gael "pride themselves on their fiscal prudence and financial management" while accusing others of being irresponsible populists:  "How did you manage to mismanage an infrastructural project of this importance and this scale so that we have a 300% increase in the cost from the original tender?"