Changes to multi-employer bargaining would help prevent a "race to the bottom" on wages, the Workplace Relations Minister says.
In a speech to the National Press Club on Wednesday, Tony Burke defended the contentious reforms as part of industrial relations laws.
Debate on the bill is set to go before the Senate in the next fortnight, with the government looking to pass the laws by the end of the year.
He said multi-employer bargaining would be one of the ways to help lift stagnant wages.
"There is no way of undoing the deliberate design feature of low wage growth without opening up the bargaining system," he said in the speech.
"When people have said all this multi-employer bargaining is too complex, what's too complex is the current system, which is impenetrable."
Critics of the proposal, including prominent business groups, have warned the bill would lead to more strikes and industrial unrest.
Mr Burke said employers and workers wanted to be protected from undercutting.
"A race to the bottom is no good for low-paid workers and it's no good for people on middle incomes either and if you want to get wages moving you need to stop the race to the bottom," he said.
"If you take the single-interest stream completely out of the equation, then it's a licence for the race to the bottom."
For the laws to pass the upper house, it will need the support of all 12 Greens senators and at least one crossbencher.
Mr Burke said negotiations were ongoing with crossbench senators, including ACT independent David Pocock, who has called for the bill to be split.
"My preference is the bill in its current form. I acknowledge there'll be negotiations and I would much sooner be in a position where we were tweaking individual sections than removing entire sections of the bill," he said.
"I really don't want to be in a situation where we're taking complete sections out of the bill, but that's a conversation we'll continue to have."
The minister said he was impatient to get the bill through to boost stagnant wages sooner.
While he said a decision on whether to extend Senate sitting days for the bill to pass rested with the upper house, he indicated he would support the move.