There's a warning about major staffing problems at the centre which takes calls and dispatches ambulances across the country.
SIPTU has written to the National Ambulance Service, claiming the National Emergency Operations Centre has fallen below the agreed staffing level by 35 workers.
The centre operates across two sites in Tallaght and in County Donegal.
SIPTU Organiser, John Mc Camley, says a similar shortfall in 2016 led to a strike at the Dublin base.
"There's now 35 permanent vacancies within the National Ambulance Centre." McCanley said.
"Around two years ago, the same levels led to a dispute at the Tallaght centre, we had an agreement to bring the staff levels up, but levels of that has not been implemented by management.
"Normally you would have 155 staff and there are 35 missing from the centre.
"That creates difficulties in terms of rosters, we have asked management to put in an action plan now and speed up the process."
