The federal opposition says the Coalition is using tough pay negotiations with public servants as a way to revive WorkChoices.
They claim staff running Centrelink and Medicare will be $920 worse off per year if the latest Department of Human Services pay offer goes through.
Labor's spokesmen on workplace relations, Brendan O'Connor and human services, Doug Cameron, said the 3.25 per cent guaranteed wage increase over three years was a real wage cut of nearly 4.25 per cent.
"Unfairness and ideological obsession are at the heart of the Abbott government's approach to workplace relations," a statement from the the two Labor politicians said.
"Tony Abbott is using the public service as a vehicle to revive WorkChoices and it is completely unacceptable."
"With inflation over the same period forecast to be around 7.5 per cent, this would see a typical worker at least $920 worse off each year.
"Worse, the government is also demanding that staff work an extra 4.5 days a year and give up allowances and sick leave."
"In one of the most perverse public sector workplace relations policies of all time, the government has said that if the department doesn't meet its 'workforce profile ratio' - code for job cuts - Human Services staff will face even lower wage increases than those on the table now," the statement said.