The peak body representing 2 million workers in Australia is pushing for a 35-hour, four-day work week with no loss of pay, arguing the reform is needed to fight burnout and lift productivity.
In its bold submission to Labor's inquiry into the National Employment Standards (NES), the Australian Council of Trade Unions also wants five weeks' annual leave and 10 days' paid reproductive leave, citing unpaid overtime and health pressures.
The union said Australian and international four‑day‑week trials show no drop in output, with many employers reporting better engagement, lower sick leave and higher retention.
Business groups have slammed the proposals, warning they would worsen labour shortages, drive up costs and harm competitiveness.
Business Council chief Bran Black urged the government to rule out 'restrictive mandates' while Australian Industry Group chief Innes Willox labelled the plan economically reckless, warning employers would be forced to pay more for less.
'Legally mandating a four-day week would be the pinnacle of magic pudding economics - requiring a smaller pie and expecting it to feed the same number of mouths,' Mr Black told the Australian Financial Review.
'Rather than focusing on increasing obligations for employers, we must focus workplace changes on increasing productivity and business competitiveness because lower productivity ultimately means a lower quality of life for Australians.'
Mr Black said businesses operate in a fiercely competitive global market and every extra mandated cost makes Australia a less attractive place to invest and create jobs.
The ACTU said there's a growing wellbeing and productivity case for a 35-hour working week.
Mr Willox said the nation was already facing labour shortage and productivity crisis.
'If anybody wanted to wantonly trash the Australian economy, this union blueprint would be the perfect place to start,' he told Daily Mail.
'By making these ridiculous ambit claims, the union movement has clearly decided to pay no attention to the broader needs of our economy, current economic data, the lived experience of Australian businesses and workers and emerging global trends ranging from trade to technology.'
'At a time of a growing national productivity and competitiveness crisis, and with the economy facing chronic labour and skills shortages, these calls should be immediately dismissed.'
Mr Willox also rejected union calls for another week of annual leave and a range of new rights to be absent from work.
'The underlying idea seems to be that Australia gives up on the idea of work, aspiration and a reward for effort.'
The inquiry, launched by Workplace Relations Minister Amanda Rishworth, will test whether the NES still meets the needs of workers and employers, with findings set to shape Labor's industrial relations agenda before the next election.
Introduced in 2009, the NES applies to all employers regardless of contracts or enterprise agreements and includes four weeks of annual leave, 10 days of personal leave, maximum working hours, and up to 16 weeks of redundancy pay.
In its submission lodged on Friday the ACTU said there was a growing wellbeing and productivity case for a four-day working week.
'Countless surveys and studies have shown that Australian workers are suffering from a significant burden of stress, overwork and burnout,' its submission read.
'A Swinburne University study of Australian firms trialling a four-day week found that none reported a drop in productivity, while most saw improvements alongside lower sick leave and higher staff retention.
'Large employers such as Medibank have also reported stable performance, stronger engagement and reduced absenteeism.
'Trials show that when hours are reduced, organisations cut low value-meetings, streamline processes and adopt smarter technology - changes that lift productivity per hour worked.'
Unions also want the Albanese government to add 10 days' paid reproductive leave to the National Employment Standards to cover a wide range of reproductive‑related health issues, from fertility treatment and miscarriage to menstrual pain, menopause, endometriosis, prostate cancer screening and vasectomy recovery.
Around 150,000 couples a year experience pregnancy loss, while 28 per cent of menopausal women report symptoms severe enough to affect their work, and 17 per cent require extended leave.
The ACTU is further seeking a rule that employees only need to provide a medical certificate for personal or carer's leave if they are away for more than two consecutive days.