Services at South Dublin County Council were disrupted today due to industrial action.
Council workers who are members of IMPACT stopped work in a dispute about pay.
The council said its offices and library services were closed due to the action by members of the union in administrative and professional positions.
Industrial action is also planned for Thursday.
IMPACT accused South Dublin County Council of unilaterally implementing pay cuts by eliminating "acting up" allowances for taking on additional duties.
A small number of SIPTU workers are also supporting the dispute.
The council apologised for what it called the uncertainty and inconvenience caused by the industrial action, which it described as "unnecessary".
National Secretary of IMPACT Peter Nolan said staff at the council have been forced to take industrial action after cuts in payment to 13 of its senior management staff.
Speaking to RTÉ News Mr Nolan said it was the intention of management to impose the cuts to an additional 150 staff at the council.
All council offices in Clondalkin and Tallaght and depots, and libraries were closed today and and will shut again on Thursday.
These offices are responsible for the issues such as traffic, housing services, water, roads, parks.