Members of the Teachers' Union of Ireland (TUI) will be balloted in September on "a co-ordinated campaign of industrial action" if an improved pay deal is not secured.
Yesterday, the Association of Secondary Teachers in Ireland has said it will ballot its members next month on possible industrial reaction.
The Irish National Teachers' Organisation said it would also ballot its members on potential strike action "unless the Government [puts] a respectable pay offer on the table".
TUI, which represents 20,500 members, urged the Government to return to the Workplace Relations Commission with "an improved proposal that appropriately addresses the current cost-of-living crisis that is having such a significant negative effect on the lives of Irish workers and their families".
Union president Liz Farrell said: "All over the country, public sector workers are struggling to meet financial commitments and the situation is continuously worsening.
"Inflation has spiralled in the months since the review clause of the current public service pay deal was triggered, so any proposed pay increases must appropriately address the resulting severe cost-of-living crisis that is having such a detrimental effect on society."
Ms Farrell said the current offer "is simply inadequate".
"Teir failure to further engage has been extremely frustrating. An improved offer is essential to avoid the inevitability of industrial unrest," she added.
ASTI President Miriam Duggan said the union's members are worried about how they will pay their bills and cope with soaring prices due to the cost of living increases.
She told RTÉ's Morning Ireland that if talks collapse and the Government "fails to make a decent and credible offer" then the union members will take industrial action.
Ms Duggan said the public service unions, including the ASTI, have decided to ballot for industrial action to prepare for the possibility that talks will fail.
However, she said that the ASTI sees "a real window of opportunity for the Government to make a realistic offer."
She would not give a figure or percentage that the ASTI is seeking for its members but said: "I want my members to be able to live and to meet their bills.
"We're looking for a way of coping with rising inflation. No more than that, I'm not going to say because the negotiators are doing their job and we have to leave them free to do it."
