THE SNP's education secretary has been chastised by a senior NHS executive after she suggested that staff were transferred from a major children's hospital to plug rota gaps at a ward in her constituency.

Tim Davison, the NHS Lothian chief executive, told Angela Constance that it was "inconceivable" that he would sanction the plan to protect the paediatric service at St John's Hospital in Livingston, saying it could risk safety at the Royal Hospital for Sick Children (RHSC) in Edinburgh, where "the sickest of children" were cared for.

HeraldScotland: St John's Hospital Livingston

The revelations come amid a growing row over the future of the West Lothian unit, following claims that Scottish Government officials attempted to delay publication of a report that could signal its permanent downgrade until after the Holyrood election to protect the interests of the SNP.

Ms Constance expressed her unhappiness to Mr Davison last summer about a temporary downgrade of the paediatrics facility, which serves her constituents in Almond Valley, documents released under Freedom of Information laws reveal. The ward was forced to operate with restricted opening hours due to staffing concerns.

The cabinet secretary said she was concerned that "it is once again St John's Hospital children's ward that has had to be closed but that children's services elsewhere remain uninterrupted".

She said she believed an agreement was in place for staff from across the hospital estate to plug rota gaps at St John's if needed and told Mr Davison he must re-open the ward as quickly as possible.

However, in a terse reply, Mr Davison said that the Edinburgh facility, which is being replaced by a new £150 million hospital, did not have staff to spare. He added: "The RHSC has multiple sub-specialty services to cover across emergency medicine/paediatric intensive care/ surgical specialties which do not lend themselves to covering general medical paediatric services at St John's Hospital.

"If not all rota slots are able to be covered across RHSC/SJH it is inconceivable that the safety and sustainability of a tertiary teaching hospital serving the whole of the south east of Scotland, dealing with the sickest of children (including those from West Lothian) would be compromised in favour of staffing the out of hours rota at the paediatric ward at SJH."

Documents also reveal that despite Ms Constance's position, Lothian health officials considered maintaining reduced hours at the ward as issues that led to the temporary downgrade were not resolved.

However, despite NHS Lothian privately saying that fully reopening the ward would "require the acceptance of a risk to patient safety" and Mr Davison advising that things should be kept as they were, it returned to a full service following pressure from the Scottish Government.

Paul Gray, the NHS Scotland chief executive, said Health Secretary Shona Robison expected the downgrade to be temporary and eventually persuaded him to reopen it 24 hours.

After consultants wrote a letter confirming they were happy for the ward to reopen on a 24/7 basis, Mr Gray told Mr Davison: "I think we will face a needlessly difficult set of external pressures and time-consuming public discourse if NHS Lothian do not reopen the ward.

"I fully understand all that has been said about long term sustainability, and value for money, but reopening the ward fully would sensibly create space and time for measured consideration of the longer term options.

"This is not about bowing to pressure. It is about giving us space to reach considered decisions through an appropriate process, rather than spending time dealing with a set of reactions that will only serve to calcify the existing 24/7 provision and make it harder to make sustainable change in the longer term."