Workplace law changes all but locked in

Changes to workplace laws and the introduction of multi-employer bargaining have cleared their last major hurdle and are set to become law by Christmas. 

The Senate passed the new laws on Thursday with the support of the Greens and independent senator David Pocock and are set to be ticked off by the government-controlled lower house.

Liberal senator Michaelia Cash vehemently opposed the introduction of multi-employer bargaining, vowing the coalition would fight for the interests of small businesses.

Senator Cash argued arguing smaller businesses will be forced into agreements and stung with legal costs they can't afford.

"This is without a doubt one of the greatest travesties businesses in Australia will every face," she said.

Liberal senator Sarah Henderson said businesses would stop employing more people to remain exempt from multi-employer bargaining.

"Why on earth would you want to grow or say 'I want to put in another 10 people'?" she said.

Trade Minister Don Farrell called the argument a red herring.

"If a business needs extra staff, they're going to be hiring," he told AAP.

"They're out there right now looking for people. The big problem is actually finding staff."

Senator Farrell said he was confident wages would lift in light of the new bargaining powers but wouldn't put a specific date on the increases.

"It gives us the opportunity to really, really get wages moving again," he said.

"There's a whole lot of industries out there where people are raring to go."

Small businesses with fewer than 20 employees will be excluded from single-interest multi-enterprise bargaining.

Businesses with fewer than 50 employees will have extra safeguards if they want to opt out of multi-employer bargaining.

The opposition wanted to increase the exemption threshold to 200 employees but failed to amend the legislation. 

Liberal senator Simon Birmingham implored the government to start with a smaller cohort of workers when introducing a radical shake up to workplace laws.

"Multi-employer bargaining is the most controversial, the most risky and the most disputed aspect of these industrial relations reform ... because of the genuine concerns businesses across Australia have," he said.

"Start with a small part of the Australian business community and see whether the concerns businesses expressed are upheld or not."

Workplace Relations Minister Tony Burke said the current bargaining system had resulted in a decade of stagnant wages.

"People should not have to wait longer for a bargaining system that works and gets wages moving," he said.

Prime Minister Anthony Albanese said the changes would increase productivity and therefore avoid a wage-price spiral, when higher salaries fuel inflation.

Mr Albanese also quoted Reserve Bank warnings that warned low wage growth was impacting the economy.

He said the current system wasn't fit for purpose.

"It's not delivering the productivity gains employers need. It's not delivering the wage rises that workers deserve," he said.

"The way you lift wages without putting pressure on inflation is to boost productivity."

ACTU national secretary Sally McManus said the laws would empower workers to negotiate better deals and recommence bargaining arrangements following the pandemic.