Cork TD Mick Barry is among those calling on the Government to appeal a High Court ruling which could open the door to pay cuts for 120,000 construction workers.
The Irish Congress of Trade Unions announced at the weekend that they had sent a letter to Tánaiste and Minister for Enterprise, Trade and Employment Leo Varadkar urging him to appeal the same ruling to the Supreme Court.
The High Court ruled late last month that parts of the 2015 Industrial Relations Act which allows the Government to make Sectoral Employment Orders (SEOs) are unconstitutional.
SEOs set minimum rates of pay and conditions across industry and since the legislation in question was passed in 2015 SEOs have been made for building workers, plumbers and electricians.
There are 120,000 workers affected by the orders employed in these industries and as long as the High Court ruling remains in place employers in these industries are not legally restrained from reducing workers' pay and conditions.
ICTU General Secretary Patricia King said that it is vital that the State appeals this judgement and seek a stay on the order pending the outcome of the appeal. She added that in the meantime unions are determined to act individually and collectively to defend their members pay and terms and conditions of employment by taking industrial action where necessary.
A number of construction workers' unions are now balloting for industrial action to allow for strikes should any employers attempt to cut pay and conditions.
The Connect trade union has warned of "war" should any such attempt be made.
"This is an early test for the new Government on the issue of workers' rights," Mr Barry said. "A door has been opened up which allows the possibility of more than 100,000 workers having their pay cut.
"That door must be slammed shut and the Government should now try to do precisely that by appealing this ruling to the Supreme Court."