Gas supplies could be disrupted later this month by strike action at gas network infrastructure company GMC Civil and Mechanical Engineering.
SIPTU has served notice of industrial action on the company in a dispute over pay and conditions.
The action will involve one-day work stoppages on Friday 19 May and Friday 26 May.
It will also include a work to rule, including no working of overtime on the same two weekends. There will also be a withdrawal of some 'second response' emergency cover during these periods.
GMC Civil and Mechanical Engineering operates the Gas Networks Ireland contract for the maintenance of gas supply.
The dispute will include the placing of pickets on five GMC depots across the country, including two in Dublin, as well as Cork, Limerick and Carlow.
SIPTU said that the company needs to take seriously the workers' claim for a pay rise and to enter into meaningful negotiations.
"Our members have been forced to take industrial action in this dispute due to the company frustrating attempts to find a just resolution during 18 months of talks concerning a claim for a pay increase and the protection of workers’ conditions of employment," said SIPTU Organiser, Andrew McGuinness.
"These workers provide an essential service maintaining and developing our gas infrastructure. They realise that taking this industrial action will inconvenience the public and could cause disruption to gas supplies.
"However, they have been left with no option as their claim for a pay rise in the middle of a cost-of-living crisis has been frustrated by the company since it took over the contract for Gas Networks Ireland in 2021," Mr McGuinness said.
SIPTU said that GMC was aware of a 5% annual pay increase claim prior to taking up the contract and the union has accused the company of failing to address it.
GMC said it is bitterly disappointed to have received notice of industrial action and added it had engaged constructively with the employees and their representatives who transferred to the company on 1 August, 2021.
"The company has not frustrated any resolution of the pay dispute and have amicably resolved pay and conditions for the majority of employees since the transfer date," GMC said in a statement.
"The matter has been referred to the WRC and we are awaiting a referral to the Labour Court. The company has always respected the machinery of the state in settling any dispute and we expect that SIPTU will also.
"The company is a member of the CIF (Construction Industry Federation) and confirms that all employees are paid in accordance with the Construction SEO (Sectoral Employment Order)," GMC said.
