Opposition parties are calling for a health board to release the full 2013 report into “worrying standards of care” at a mental health unit.

The Holden Report warned the Hergest unit at Ysbyty Gwynedd, Bangor, was “in serious trouble”. A redacted summary was released in 2015.

In June, the Information Commissioner’s Office told Betsi Cadwaladr health board to release the full report after a Freedom of Information request.

But it appealed against the decision.

The health board said “publishing this full report would breach the confidence of those members of staff who contributed to it”.

A review of the 42-bed Hergest psychiatric unit was commissioned after complaints by staff.

The report’s author, Robin Holden, said staff relationships had “broken down to a degree where patient care is undoubtedly being compromised”.

In a statement at the time, Betsi Cadwaladr said action had been taken to address the report’s recommendations, including a restructuring of the board’s management of mental health services.

A separate inquiry into the Tawel Fan mental health ward at another north Wales hospital – Ysbyty Glan Clwyd – led to the board being put into special measures by the Welsh Government in 2015. The board remains in special measures to this day.

On 8 May 2019, a request was made for “a copy of the full Robin Holden Report, redacted only to the extent needed to protect patient confidentiality and the identity of the whistleblowers”.

The request was refused, leading to a review of the decision by the Information Commissioner.

In a decision notice issued on 30 June, Catherine Dickenson from the Information Commissioner’s office upheld the complaint and called on Betsi Cadwaladr to “disclose a full copy of the report with only the names of individuals subject to the grievances redacted”.

But Betsi Cadwaladr has this week appealed against the decision.

The health board’s interim chief executive Simon Dean said: “We have a duty of care to our employees and are concerned that publishing this full report would breach the confidence of those members of staff who contributed to it.

“Since this report was produced in 2014, we have taken a range of actions to improve standards of care on the Hergest Unit.

“Reports from unannounced inspections of the unit by Healthcare Inspectorate Wales show that standards of care, staff morale and leadership arrangements have improved in recent years.

“We encourage anyone with concerns about the care that they or a loved one have received to contact us directly,” he added.

Conservative Member of the Senedd for Clwyd West, Darren Millar said: “The deliberate attempts to stifle its publication are unhelpful and undermine trust between the health board and the people it serves.

“The public have a right to know whether scandals such as Tawel Fan could have been avoided and the publication of this report may help to shed a light on these issues.”

Plaid Cymru’s health spokesman called on Wales’ Health Minister Vaughan Gething to intervene “to ensure that this cover-up comes to an end now”.

Rhun ap Iorwerth MS said: “Family members have fought hard to get this document out into the open. The health board’s management have fought to keep it secret every step of the way and that begs many questions.

“If there’s nothing wrong, what have you got to hide?”

Speaking on BBC Radio Wales’ Sunday Supplement programme, Labour’s MS for Wrexham and the Welsh Government’s Environment Minister, Lesley Griffiths, said: “I think if you can publish information, it’s always good to be very transparent and this is something obviously the minister for health and social services will be discussing with the health board.”