Unions are criticising moves to introduce pay parking for staff at St James's Hospital.
The situation has the potential to cause a strike at the facility.
Staff were told before Christmas they'll have to pay up to 500 euro for their spaces, due to the construction of the new National Children's Hospital.
SIPTU says it's unacceptable for management to try to remove an integral part of staff terms and conditions without any engagement.
The union is now going to ballot members which could result in strike action.
A spokesman for the hospital said getting staff to use public transport was a key objective and that St. James has more public transport links than any other hospital in the state.
