The minimum wage must be increased significantly in order to prevent the emergence of a two-tier workforce.
The Irish Congress of Trade Unions said a rise was needed to keep pace with wage growth and price rises since 2005.
David Begg, Congress general secretary, said the number of people earning the minimum wage has increased by 40 per cent since its introduction in 2000. More than 100,000 employees are now on the minimum wage.
In a submission to the Labour Court, Mr Begg said: "This trend is likely to continue. "Unless we see a significant rise in the minimum wage, this could lead to the emergence of a two-tier workforce, with very negative consequences for the economy and society.
Mr Begg said 7 per cent of those in work are at risk of poverty. "It is clear that the minimum wage can be utilised both to combat inequality, address the problem of low incomes and help close the gender pay gap," the Congress chief said.
"We must also remember that this is the only, legally-enforceable wage rate covering the whole economy. Thus, it has a crucial role to play in the protection and enhancement of labour standards generally by setting a threshold of decency below which no employer can legally go.
"In the context of strong inward migration and the protection of all workers, there is a compelling case for a significant rise now." The minimum wage currently sits at €7.65 per hour and it was last adjusted upwards in May 2005. The minimum wage was to be set at 60 per cent of median earnings, as recommended by the National Minimum Wage Commission, prior to its introduction in 2000.
But Mr Begg claimed the level has consistently fallen below 60 per cent falling as low as 47 per cent, in 2003. It currently stands at just under 51 per cent.
The Congress submission claimed all evidence indicated the minimum wage increase in 2005 had not contributed to a growth in unemployment, if anything, the opposite had happened.
Mr Begg also said a rise would also have no impact on inflation or affect competitiveness.
PA