The Tánaiste has moved to defend the spiralling cost of the new National Children’s Hospital in Dublin.

It has been reported that the facility - now expected to cost the taxpayer €1bn - will be the most expensive of its kind built anywhere in the world.

The price-tag will also place the facility among the world's 20 most expensive buildings.

The cost of the construction has more than doubled since 2012 when it was expected to cost €404m.

The development has faced significant opposition since it was announced - with campaigners insisting the facility should be located on a greenfield site closer to the M50.

The “Connolly for Kids” group have claimed there is no “single justifiable reason for locating the Children's Hospital on the St. James's site.”

The group have advocated for the hospital to be constructed on the Connolly Hospital site in Blanchardstown.

Inflation in construction costs

In the Dáil this afternoon, Sinn Féin deputy leader Mary Lou McDonald called on the Government to explain how it can stand over the price - which does not include IT and equipment.

The Tánaiste Frances Fitzgerald blamed rising inflation in construction costs and insisted the government is committed to ensuring that the funding will be available.

She said the original price was estimated when construction inflation was thought to be at 3% adding that it is now running at higher than 9%.

“There are also extra facilities that were not in the originally plan like the education and research centre which will be funded from elsewhere,” She said.

“When it comes to capital costs, it is quite clear that many of our major projects have had costs overrun.”

She insisted the project will go ahead as planned.

“We absolutely need to have our children’s hospital,” she said. “Of course we will go ahead; it has already begun and will be delivered in the near future and will work according to plan.”

Deputy McDonald claimed the Tánaiste had been "evasive" in her response and called the saga further evidence of the government's "neglect" of the health service.

"Today, twenty-four years after the idea was first proposed in 1993, the National Children’s Hospital is still a project wrapped up in uncertainty and chaos," she said.

"The abject failure to get a handle on the astronomical costs of the children’s hospital, and allay the fears of parents, is proof positive that Fine Gael and this government is utterly bereft of leaders."

Best in the world

The Children's Minister Katherine Zappone said that if the new facility is going to be the most expensive children’s hospital in the world - it should be the best.

“It is really important as you know that we need a children’s hospital; that it is done in the best possible manner - but we also need to ensure that the costs are appropriate,” she said.

“One of the things I think that could be considered is that the Public Accounts Committee maybe take a look at the costs issue.”

The committee is expected to call in the planners over the coming days to explain the spiralling costs of the development - but as things stand, they are still expected to get the green light in the summer.