A one-day strike scheduled for today at the State's 43 National Car Test centres has been called off after management agreed to limit the use of spy cameras on staff.
However, the AGEMO trade union, which represents the majority of staff, said industrial action remained likely in the coming weeks as the concessions did not go far enough.
Mr Frank Jones, trade group official with AGEMO, the mechanics' and drivers' division of SIPTU, which represents about 270 NCT Service (NCTS) workers, said its strike committee would decide either today or tomorrow when exactly it would hold its one-day strike.
"If there is no favourable response from management we will have to go ahead with the day of action."
Today's strike was called off after NCTS forwarded proposals to the union on limiting the use of spy cameras and surveillance in monitoring work performance.
However, Mr Jones said workers were demanding the removal of all hidden cameras which were used for such monitoring purposes, as well as assurances that no staff members would be subject to scrutiny outside of work by private investigators, as had occurred in the past.
"The only assurance we got from management was that they had no private investigators on their payroll at the moment."
Notice for strike action was issued last month after the suspension of a union activist in Naas, Co Kildare, for an alleged breach of discipline.
His was the fourth such suspension in recent months - the others coming in Dublin, Tipperary and Wicklow.
Mr Jones said the union had last Friday informed the company of its rejection of the management proposals.
However, a spokeswoman for NCTS, which is owned by the Swiss-based multinational SGS Group, denied this.
"We are in the dark. They have not made any attempts to tell us they are unhappy with the proposals," she said.
