The Government is being urged to ditch plans for tax cuts in the Budget.
Social Justice Ireland says investment in infrastructure, and tackling inequality would be better for the economy.
The campaign group believes proposals like broadening the lower tax band, and cutting the USC will not benefit lower income workers.
Dr Sean Healy of Social Justice Ireland says the tax band proposals are not fair.
"It means that you have to be earning €33,800 to actually benefit from that tax change," he said.
"It would mean, therefore, that well in excess of a million people with jobs would not benefit at all from that tax changes that were brought in in the Budget, and that the million that would benefit are the people with incomes above €33,800."