The new minimum wage of €7.65 comes into effect today.
Unions and community groups are joining forces to urge the Government to reverse the decision to cut the rate by €1 per hour. They will protest outside the Dáil later today.
SIPTU Spokesperson Ethel Buckley said the reduction in wages could not be sustained by people on low incomes.
"Low-paid workers can't afford to take this additional cut," she said. "They've already had their wages cut by the income levy last year, the Universal Social Charge, changes to the tax bands, reduction in Child Benefit…
"We're being told by people on the ground that this will drive them into poverty."