Nurses say they could be forced to take to the pickets as a result of the HSE's continuing recruitment ban.
The job freeze was introduced earlier this year as part of a plan by health service managers to reduce major budget over-runs for 2007.
SIPTU nurses say the measure is laying the groundwork for problems for workers and patients, as pressure mounts on Irish hospitals.
The union says industrial action may be the only way of highlighting the problem and the effect it is having on hospital services.