Trade unions believe people need certainty in their employment if they are going to spend, an essential ingredient in Australia's recovery from last year's recession.
Unions and Labor are at loggerheads with the Morrison government over planned industrial relations law changes, which the federal opposition claims will cut workers' wages and entitlements.
Labor leader Anthony Albanese outlined his party's plans for workplace law in a speech last week, but a lack of fine detail left open the opportunity for the government to claim the plan would be $20 billion tax on business.
"In their rush to distract from their own plans to cut pay and make work less secure in our economy, they came out with this fictional figure," shadow treasurer Jim Chalmers told Sky News' Sunday Agenda program.
"So I don't accept the figure. I don't accept it is based on anything like what we announced."
He said Labor wants to work closely with business on the challenges in the economy, such as stagnant wages, underemployment and job insecurity.
"That all flows into declining living standards and weak business conditions," Dr Chalmers said.
Among the changes, the government is proposing that a casual worker should get the choice to become a permanent employee after a year, but that conversion is not guaranteed.
ACTU secretary Sally McManus would prefer that proposal came in after six or nine months.
"If the job is a permanent, ongoing job, you should have permanent rights," she told ABC's Insiders program.
"At the moment, what the government is saying is that employers can have reasonable grounds and that reasonable grounds would be if they just decide they don't want to and you can't even go to the independent umpire and get that challenge."
Asked if making a casual worker permanent under this proposal would put an additional cost on the employer, Ms McManus said: "No, because the employee would then not get the casual loading."
Industrial Relations Minister Christian Porter jumped on this response, while sticking with his $20 billion calculation of Labor's policies.
"What is now being revealed is the plan is to decrease that cost to business by taking away casual workers' 25 per cent up front wage loading," Mr Porter said in a statement.
"What makes this policy so unfair is the worker gets no choice because Labor and the union movement want to decide for them, because under Labor's proposal workers don't get a choice about whether to stay casual and hold on to the 25 per cent loading or go permanent."
Still, Ms McManus believes when people have certainty in their jobs, they are more likely to spend their money, essential in the economic recovery.
"That's the 12 million people that are going to be spending in local businesses," she said.
"If we go about doing what the government is proposing and that is to reduce wages, to make jobs more insecure, we will spend less - that's not going to be good for the economic recovery."