ICTU General Secretary David Begg has described suggestions that the minimum wage could be reviewed as 'toxic'.
He said any such proposals would not be tolerated by unions.
Speaking at the MacGill Summer School in Glenties, Mr Begg said there is no way he would tolerate any reduction.
The trade union leader added that things cannot be allowed get to the point where there is no 'threshold of decency' beyond which proposals will not go.
His comments came in response to suggestions that the Government may consider cutting the minimum wage if it becomes an obstacle to job creation.
The warning came from Minister for Finance Brian Lenihan, who said changes would be based on a review of individual sectors where the minimum wage is having an impact.
Speaking on RTE's Morning Ireland, Fine Gael spokesman on Enterprise, Trade and Employment Leo Varadkar said he did not believe that the minimum wage was an obstacle to the provision of jobs.
NAMA legislation
The minister also said that progress has been made in preparing the legislation for the National Asset Management Agency.
However, Labour leader Eamon Gilmore is critical of delays in setting up the agency.
He said that the biggest problem with the legislation is the delay in implementing it as it is creating uncertainty in the banking sector.
