But Donald Cameron, the Scottish Tories’ Shadow Health Secretary, said: “To now discover that this delay was down to a mistake in a spreadsheet is absolutely astonishing, and frankly beggars belief.

“The whole episode of the new Sick Kids Hospital in Edinburgh has been woefully mishandled by the SNP Government and the current inquiry must ensure that those responsible do not get away with their collective failures.”

NHS Lothian asked audit firm Grant Thornton to conduct a review of the health board’s role in the project, the first NHS hospital to be built using the Scottish Government’s private financing model known as Non-Profit Distribution (NPD).

Its report, disclosed by BBC Scotland, said there was “collective failure from the parties involved” and that it was “not possible to identify one single event which resulted in the errors”.

But it said a determining factor was the decision, taken in 2010, to have 20 four-bedded rooms, three of which were for critical care and therefore required better ventilation.

The report said “this was missed from the outset of the project and remained unidentified until June 2019”, the month before the hospital was due to open.

One of the three construction firms bidding for the work changed the spreadsheet to include the correct air changes in their tender but they did not win the contract.

Calum Campbell, chief executive of NHS Lothian, said: “We would like to acknowledge the extent of analysis that the chief internal auditor has undertaken, particularly the review of complex and significant documentation which relates to the project and spans 12 years.

“Some areas identified have already been addressed and others will be implemented within the agreed time frames to ensure that future capital projects will benefit.”

The Scottish Government highlighted the public inquiry, saying the safety and well-being of patients and their families was their top priority and should be the “primary consideration in all NHS construction projects”.

Source Article