The Taoiseach says it's scandalous that the Government agents got the cost of the new National Children's Hospital project so wrong.
Earlier this month, the Health Minister Simon Harris insisted that the overspend on the project is not a scandal.
The projected cost of the project has spiralled to at least €1.7bn over recent months - up from the original €650m estimate.
Leo Varadkar says mistakes were made, but he says no one will be sorry when the project is finished.
"It's scandalous that the Government - or rather the Government's agents - got the estimate of the cost of this project so wrong".
"We can't take credit for getting things right for balancing the books, if we don't also take responsibility for this.
"Our agent certainly made some big mistakes in calculating what this project was going to cost.
"But there's one thing I'm absolutely sure of, and we should never forget this: we shouldn't ever forget the value of this project.
"This is going to transform paediatric healthcare in Ireland.
When this is commissioned in 2023, nobody will be sorry that we made this investment".
On Brexit, he said Ireland would need hundreds of millions of euro of funds in the event of no-deal.
"If we're in a no-deal scenario in a couple of weeks time, we'll be looking to find hundreds of millions of euros to bail out the beef industry, to save jobs in agri-food, to save jobs in small exporters around the country.
"That'll be the money we're looking for, rather than the money for additional infrastructure".
On the national broadband plan he said: "My view is that if we don't make broadband available to all parts of the country... then we're going to leave hundreds of thousands of people behind.
"It'd be almost like not doing rural electrification - so I'm a big supporter of this, but we do need to get it right".