Hundreds of sales workers and charity fundraisers are hoping to recoup millions of dollars in lost pay in a lawsuit targeting two direct marketing companies.
The National Union of Workers on Monday filed group actions in the Federal Court in Sydney against Aida and Credico Australia.
The union alleges they engaged in sham contracting of workers, who were tasked with selling products door-to-door and in shopping centres for the likes of Telstra, Optus and Foxtel, as well as charity fundraising.
The court action is on behalf of 100 workers, but the union says that could rise to 500 or even 1000.
The NUW claims thousands of other workers are also affected by the alleged underpayments, earning $400 to $500 for up to 70 hours of work a week - well below the national minimum wage.
"This is wrong," assistant branch secretary Godfrey Moase told reporters outside court.
"We're aiming to set a precedent that means independent contracting can no longer be used as a way to steal workers' entitlements, to steal workers' wages, and to steal workers' time."
It's claimed each worker is owed between $50,000 and $80,000 for a year or 18 months worth of work, opening the door to a multi-million dollar compensation claim.
"The end game is that every single worker in direct sales is ultimately paid a lawful minimum wage and that they have the rights that accord to being an employee under Australian law," Mr Moase said.
The action is being funded by a litigation financier with a budget of more than $1 million.
Adero Law's Rory Markham hopes the suit - if successful - is a "shame point" for large corporates that employ direct marketing firms that "take advantage" of vulnerable Australian workers.