NHS Lothian's chief executive has told STV News he considered resigning over delays to Edinburgh's new children's hospital.

Tim Davison said it was "the biggest single crisis" he had faced during 37 years working in the health service.

The new building at Little France was due to open in July - following a series of previous delays - but health secretary Jeane Freeman stepped in to block that following concerns over the ventilation system.

In his first interview since that decision was made, Mr Davison said: "I've considered my position very, very carefully.

"This is probably the biggest single crisis of my entire career and I've worked in the health service for almost 37 years.

"So, of course I have given consideration to my position here. I am absolutely focused at the moment on concentrating on supporting my team to getting this building occupied and that's the focus I want to give for now.

"I'm not in any sense ducking my accountability for this, but I think my personal role in this has been professional.

"My focus is to try and get this hospital opened, which is what our patients and our staff want to see."

Mr Davison revealed the building had passed independent tests in February, leading the health board to believe it was complete and safe.

However, just a week prior to the opening date in the summer, it was discovered the ventilation system in the critical care department was not capable of delivering the rate of ten changes of air per hour as required by the regulations.

The system is now being redesigned to meet that requirement.

Last month, Ms Freeman told parliament the problem had stemmed from an error in a document produced by NHS Lothian some years ago and that opportunities to spot that had been missed.

Mr Davison said: "With the benefit of hindsight, we should have taken longer with the commissioning of the building.

"We were expecting this building to be compliant and when the tests were done that suggested some wards were not compliant, we didn't have enough time to reassess what we could do before the planned move."

The hospital is now expected to open next autumn and in the meantime children continue to be treated at the old Sick Kids - a building dating back to the Victorian era.