First Union general secretary Robert Reid says a government bill introducing a new youth wage sends the wrong message to young people about how the country values them.
The legislation extends from three to six months a scheme giving employers the option of paying 16- and 17-year-olds a lower rate; it also brings 18- and 19-year-olds who have been on a benefit into the scheme.
The Government says it will be an incentive for employers to take on younger workers but Mr Reid says it is unfair and inconsistent with the Bill of Rights.
"What a way for people to start out their lives, feeling that they are undervalued and underpaid," he says, adding that people already struggle to get by on the mimimum wage and the legislation puts even more financial pressure on young people in particular - some of whom may have started families at 18 or 19.
"Even if they haven't," Mr Reid says, "look at the rents that young workers have to pay. How could they actually exist on even the current minimum wage let alone a minimum wage of $10.80?"
The union is supporting the Green Party's complaint to the Human Rights Commission over the legislation.
