Five days of strike action by Community Employment supervisors will take place next month.
It is due to a row with the government over pensions.
It follows a Labour Court recommendation in 2008 to introduce a scheme for employees, which today has not been put in place.
The strike by SIPTU and FORSA members will start on May 13 and will disrupt community services, including childcare, elder care and disability services.
Kate Campbell, a CE Supervisor in County Donegal, said: “Escalating this dispute will have a devastating effect on both our CE scheme participants and the communities in which they work.
Participants will not get paid and progress in community schemes will be halted due to the lack of supervisory management.
Fórsa Services and Enterprises Head of Division, Angela Kirk, said: “We have contacted the Minister for Finance, Paschal Donohoe, requesting a meeting to discuss the implementation of the Labour Court recommendation.
“To date neither the Minister, nor his officials, have responded to this request despite the provisions established as part of the Lansdowne Road Agreement to establish a high level forum to deal with the issue of pensions for CE Supervisors and other matters relating to the community and voluntary sector.”