INMO assistant director of industrial relations Liam Conway said the ballot had come at the end of a long process in which the union had attempted to resolve the ongoing staffing and patient flow issues within CUH’s theatre department.

"Our members have lost confidence in the hospital’s ability to address these concerns through normal engagement channels, and have now been left with no option but to escalate the matter,” he said.

Mr Conway said nurses in the department are owed more than 5,500 hours of time-in-lieu but are unable to take it due to persistent overruns on theatre lists and insufficient staffing.

He claimed there had been continued occurrences of staff working past their shifts due to what he called poor scheduling and overruns.

“Our members have raised issues regarding patient safety, delayed and late starts of cases, lack of post-op beds for recovery, and the reliance of members to work past their rostered hours,” said Mr Conway.

“CUH management are well aware that they are in breach of national agreements when it comes to the management of its theatre department scheduling.

“The absence of progress on the matter of safety of our members, patients, and the breach of a national agreement, our members are left with no alternative but to escalate our dispute.”

Cork-based Labour Party senator Laura Harmon said CUH staff in the theatre department deserve safe and fair working conditions.

“It’s extremely alarming that 5,500 hours of time in lieu are owed to staff. This is a public safety issue as well as a workers’ rights issue,” she said.

“We need proper national workforce planning for our healthcare service across the board and the rights of healthcare staff must be upheld in CUH and in all healthcare settings.’’ 

The HSE was asked for comment.