Ripped-off workers could have unpaid wage claims of up to $100,000 resolved in a day under a federal Labor government.
Bill Shorten will promise to establish a new jurisdiction to sit alongside the Fair Work Commission to crack down on "wage theft".
"It shouldn't be too hard, it shouldn't be too costly, to get what you are owed for a day's pay," he said.
Lengthy and costly court proceedings too often deterred people from pursuing underpaid wages, he said.
The proposed new jurisdiction would be able to mediate claims, as well as make and enforce orders for repayment of wages.
Claims brought forward by a group of workers against a single employer would also be allowed.
People in remote and regional areas would be able to access the new body, including through video conferencing.
Unions and employer groups would be able to represent parties in disputes.
Labor would spend $3.7 million a year to expand a grants program, which was currently used only by community legal centres, to make it easier for workers and employers to present their cases.
"Scandal after scandal has made it clear that workers' exploitation and systemic wage theft is widespread," Mr Shorten said.
"But the Abbott-Turnbull-Morrison government has failed to act."
The Labor leader will campaign in Western Australia on Wednesday, starting with a business breakfast in Perth.
Mr Shorten and his wife Chloe arrived ahead of his keynote speech, which will offer bosses and workers a "win-win" approach.
Shadow treasurer Chris Bowen, opposition Senate leader Penny Wong and WA Labor Premier Mack McGowan are also at the event.
Mr Shorten is expected to ramp up his attacks on controversial businessman and Senate hopeful Clive Palmer.
"Thanks to the preference deal he's done with Scott Morrison, Clive Palmer can turn up on day one with a political IOU almost as big as his ego," he will say.
The opposition is eyeing up to four seats in WA, with Hasluck, Stirling, Swan and Pearce all on the radar.
Mr Shorten will also pledge $12 million to boost the number of female tradies.
Industrial relations and wages have been key policy targets in Labor's pitch to voters.
A Shorten Labor government would also restore penalty rate cuts in some industries and push the independent umpire to make the minimum wage a "living wage".
If the opposition wins on Saturday, it has also pledged to ensure labour hire workers get the same pay for the same job.
Mr Shorten is promising to consult with unions, bosses and others on the final model of the small claims tribunal.
"But our aim is to make it more affordable and accessible to bring claims forward," he said.
With the winning post approaching, Mr Shorten targeted seats in Tasmania and South Australia on Tuesday.
He'll make a major speech in western Sydney on Thursday at the Blacktown Civic Centre - the place where in 1972 Gough Whitlam delivered his iconic 'It's Time' address.
The election winning speech began a tradition of Mr Whitlam beginning with the words first delivered by wartime Labor Prime Minister John Curtin: "Men and women of Australia!"
Australian Associated Press