SIPTU members employed in community organisations in counties Waterford and Galway have announced a 24-hour work stoppage on Wednesday 6 July as part of a pay dispute.
The strike is linked to a wider campaign by workers in the sector who say they have not had a pay rise in 14 years.
The organisations involved in Co Galway are Galway Rural Development, Galway Rape Crisis, EmployAbility, the Oranmore CE Scheme and the Claregalway/Annaghdown CE Scheme.
In County Waterford, the organisations involved are Active People Community Group, Ballybeg CDP, Cappoquin Community Employment, Caring in Waterford, Compact Community CE Scheme, Tay Valley CLG and West Waterford GAA Clubs.
At the weekend, SIPTU members in the Irish Wheelchair Association (IWA) announced they would engage in a work stoppage on 5 July as part of the long-running pay dispute.
The IWA workers say that although they do essentially the same job as HSE healthcare assistants, they are paid considerably less.
The Irish Wheelchair Association is a 'Section 39' organisation contracted to provide services on behalf of the HSE for a funding grant in accordance with Section 39 of the Health Act 2004.
The IWA says it cannot increase pay for staff without an increase in its HSE Section 39 grant.
"IWA has written to the HSE to request that they urgently agree to fund an increase in the pay of IWA staff in line with public sector pay increases, which they had always done until 2008," the association said in a statement.
"The Irish Wheelchair Association fully understands and accepts the frustration of our staff which has led to this industrial action," the IWA added.
"This situation is due to the failure of successive Governments to adequately fund the community sector and Section 39 organisations," said SIPTU Public Administration and Community Division Organiser, Adrian Kane.
"This has resulted in our members being left way behind in terms of pay and conditions because of a break down in a previous link between their terms of employment with those of workers in the public sector," he added.
Across the country, workers in other care and community organisations are also conducting ballots for industrial action as part of the 'Valuing Community' campaign, which is supported by SIPTU, ICTU, Fórsa and the INMO.
The Department of Health has previously said that because Section 39 organisations are privately owned, setting pay rates for their staff is not a matter for the Government.