Image copyright PA Media Image caption The first minister and health secretary have both expressed their frustration at the latest delay to the new hospital

Nicola Sturgeon has said she "deeply regrets" that Edinburgh's new children's hospital will not open for at least another year.

The first minister was speaking at Holyrood as opposition parties called for "heads to roll" over the delay.

The hospital was supposed to open in 2017 - but will now not be ready until next autumn at the earliest.

The Tories said the project was a "shambles" and accused the government of "burying its head in the sand".

And Labour called for a public inquiry into what has gone wrong with the construction project, which has been hit by a series of delays and cost increases over the years.

Staff and patients were preparing to move into the new £150m Royal Hospital for Children and Young People in July when last-minute inspections found serious problems with the ventilation system in the facility's critical care unit.

A report published on Wednesday said £16m of repairs were needed to fix the ventilation and other issues that had been identified, with the work expected to take at least a year.

At first minister's questions on Thursday, Scottish Conservative interim leader Jackson Carlaw criticised the "absolute shambles" surrounding the new hospital.

And he accused Health Secretary Jeane Freeman of doing "too little, too late" to address the problems with the project.

Image caption Staff and patients were preparing to move into the new hospital in July when problems with its ventilation system were found

Mr Carlaw said: "The Sick Kids' Hospital is just 10 minutes' drive from where we all are now and yet it seems that four successive health ministers chose either not to know or simply failed to ask about the full extent of the problems faced until way, way too late.

"This is a saga from which nobody emerges well. Not the health board, not the contractor and certainly not this government - and it's altogether sadly too predictable.

"I think the country thinks - for once - heads should roll."

Ms Sturgeon said it would be an "understatement" to say she and Ms Freeman were angry about the "unacceptable" situation at the hospital, and insisted the government's focus was on "putting this right".

But she said the hospital would not be allowed to open until it was fully safe for patients.

Ms Sturgeon said the two reports released on Wednesday showed that the ventilation issue that had caused the latest delay did not come to light until the start of July.

Image caption Staff were preparing to leave the old Sick Kids hospital when the latest problems with the new building were found

The first minister said: "I didn't know about that, the senior management in the health board - as far as I'm aware - didn't know about that and the health secretary didn't know about that.

"As soon as that came to light, the health secretary acted properly and appropriately.

"It would have been wrong to allow that hospital to open before assurances about patient safety could have been given."

Ms Sturgeon added: "I deeply regret that the hospital will be opening late - extremely late - and it is important that we make sure that every issue that has been identified is addressed so that when it does open it is safe for the patients who use that hospital."

Image caption The Royal Hospital for Children and Young People will have 233 beds when it does finally open

Scottish Labour leader Richard Leonard asked Ms Sturgeon whether she understood "just how angry people are about this?"

He said: "We've got a children's hospital in Edinburgh that can't open its doors, and we were reminded at the weekend that we have a hospital in Glasgow built by the same contractor that has been closing its doors to a children's cancer ward.

"We need to get to the bottom of this. We need full public transparency to restore public trust, so what will it take for the first minister to finally listen and deliver a full public inquiry into this abject failure of governance and government?"

The new 233-bed hospital will form part of the Royal Infirmary of Edinburgh campus at Little France, and will provide care for children and young people up to about 16 years of age.

It will also have 10 theatres and a children's emergency department.

The building shares the same main contractor and design as the Queen Elizabeth University Hospital in Glasgow, which has also had problems with ventilation systems.

What was announced on Wednesday?

An independent review was published which found that the main issue with the critical care unit's ventilation stemmed from an error in a document produced by NHS Lothian in 2012.

It said that the error led to confusion over the interpretation of building standards and guidance, and that opportunities to spot and rectify the error were missed.

The ventilation issue also affects the oncology and haematology departments.

Ms Freeman said that a troubleshooter would be brought in to help manage the project, and revealed that the new building would not open until at least the autumn of next year.