Nurses in the public sector are being paid 20% less than agency workers doing the same work - resulting in staff shortages in the public health service, according to the Irish Nurses and Midwives Organisation.
INMO General Secretary Phil Ní Sheaghdha said the differential between pay in the public service and in agencies supplying workers to the Health Service Executive highlighted the fact that pay in the public service is now below the real market rate.
She said that according to figures obtained by the union, agency nurses and midwives were now costing the HSE over €1.4m per week, and claimed that figure could top €100m in a full year.
The INMO cited the Xtra Nursing Agency, which now pays an hourly rate at least 20% higher than that in the public sector.
In addition, the union claimed nurses in their first five years of employment are "bumped up" to the fifth increment on the pay scale.
The INMO says this means that a newly qualified agency nurse earns an extra €13,000 - or 46% more than her directly employed public service colleague. The differential for a senior staff nurse would be around €10,000 or 20%.
In addition, the INMO claimed that the Scottish Nursing Guild, which also supplies personnel to the HSE, offers rates 20% higher than the public sector.
However, agency staff do not enjoy certain public service benefits including guaranteed pensions and tenure.
The INMO has been campaigning for a 12% across-the-board pay rise for nurses and midwives, which it argues is essential to address recruitment and retention difficulties.
However, the Public Service Pay Commission categorically rejected such a proposal, and instead recommended a €20m package of allowances targeted at the worst hit areas of the health service.
Members of both the INMO and the Psychiatric Nurses Association rejected the PSPC proposals by around 95%.
Ms Ní Sheaghdha said it was time to face facts and accept that the public health service cannot hire enough nurses and midwives on current wage rates.
She said that until the Government meets unions directly to negotiate what she called "realistic" wage rates, the health service would continue to be understaffed, and waiting lists would continue to grow.
Responding to a query from RTÉ News, the HSE failed to either confirm or deny the INMO figures.
It would only say that public sector pay rates are a matter for Government.
It said agency staff are recruited through the National Framework Agreement for Agency Services.
The HSE noted that the INMO had rejected the recent PSPC recommendations, but said the matter would be considered through the appropriate industrial relations framework.