The NSW Nurses and Midwives' Association has launched legal action against the state government.
The nursing union says patients are receiving inadequate care and in its plans to file a case in the Supreme Court, it accuses the government of repeatedly breaching award conditions.
NSW Nurses and Midwives Association branch delegate Kathy Chapman told the Newcastle Herald earlier this month staff at Maitland Hospital were burning out.
She said, ahead of the March 25 election, that some members were contemplating voting for the Greens in the hope the minor party could force Labor or the Coalition to adopt ratios in legislation.
The nursing union says widespread non-compliance with staffing levels has resulted in patients not receiving over 100,000 hours of nursing care at multiple public hospitals.
Nurses and midwives have held repeated industrial action over the past year calling for mandated "safe" staffing ratios, along with better pay and conditions.
NSW has fallen behind other states in implementing legally mandated ratios, with Victoria, Queensland and the ACT already introducing them, while South Australia and Western Australia are both progressing measures, according to the association.
The association identified Gosford Hospital on the Central Coast as the worst offender for staffing breaches, with 777 award contraventions over a four-year period.
"The 1484 contraventions we are filing today are just the tip of the iceberg," General Secretary Shaye Candish said.
"If anything, we have been conservative in this prosecution and have not included a large number of other hospitals that also breached the award repeatedly."
Both major parties are taking policies to the March 25 election they say will increase the number of staff on wards, while citing budget limitations in directly meeting the union's requests.
Health Minister Brad Hazzard accused the association of using members' money to run a political campaign against the government.
"They know damn well the opposition is not planning on giving them ratios," he said.
Ms Candish says the shortages are putting patients at increased risk of adverse outcomes such as falls, pressure sores, blood clots as well as hospital acquired infections like pneumonia.
"We are talking about hundreds of thousands of nursing care hours not provided on general medical and surgical wards, meaning patients may have missed timely care, such as blood pressure checks, wound care, or showers due to inadequate or unsafe staffing," Ms Candish said.