Confectionery giant Cadbury has lost its Federal Court bid to reduce personal leave entitlements for workers at its Hobart site despite the federal government intervening in the company's favour.
Cadbury's US-based parent company Mondelez took Tasmanian employees Natasha Triffitt and Brendon McCormack, and the Australian Manufacturing Workers Union, to court over a clause in their 2017 enterprise bargaining agreement.
Ms Triffitt and Mr McCormack usually work three 12-hour shifts per week. They were entitled to 96 hours of paid personal and carer's leave per year - the equivalent of eight shifts.
Under the National Employment Standards, workers are entitled to 10 days of leave.
The AMWU argued this put the workers at a disadvantage to others who work standard 7.2-hour days, as their leave would be exhausted sooner just because they work longer shifts. The union argued the workers on 12-hour shifts should have 120 hours of unpaid leave - the equivalent of 10 shifts.
The full bench of the Federal Court was required to consider the matter, including analysing the definition of a "working day".
Mondelez argued a working day was the total number of working hours in the week divided by five - a "notional day" - and that figure was then multiplied by 10 to determine the 10 days of leave.
The AMWU argued a working day could effectively be seen as a singular unit of a day when someone works - a "calendar day" - and all were entitled to 10 days of leave.
The former Minister for Small and Family Business, Workplace and Deregulation Craig Laundy intervened in the proceedings, but the court found his submission had "substantial overlap" with the Mondelez submission.
In its majority ruling handed down on Wednesday, the court rejected Mondelez's notional day concept and found the company's argument "places too much emphasis upon the monetary value of paid personal/carer's leave".
"Since the leave is intended to act as a form of income protection during periods of inability to work due to illness or injury, rather than a mere entitlement to paid time off work, there is no inequity," the ruling reads.
"Randomness is inherent in the concept of personal/carer's leave.
"The mere entitlement of some employees to what may amount to a greater number of hours of paid personal/carer's leave than other employees, will not necessarily translate to a difference in the entitlement to take leave.
"However, each employee will be equally protected against his or her loss of earnings should the need to take leave arise. That does not seem inequitable."
Justices Mordy Bromberg and Darryl Rangiah ruled against Mondelez's two declarations, while Justice David O'Callaghan ruled in favour on its second declaration but was defeated by majority.
AMWU: 'Sweet victory' for workers
The AMWU welcomed the ruling, and believed it could have implications for two similar cases before the Federal Court.
The union was also concerned with the federal government's intervention in the proceedings.
AMWU Tasmania state secretary John Short said workers should be entitled to their full hours of leave.
"Shift workers around Australia can breathe a sigh of relief today thanks to AMWU members Natasha and Brendan who stood up against Mondelez and won this case," he said.
"If you need to take a sick day, you should be paid for your normal hours of work, it's as simple as that. And you should be able to take 10 sick days paid at your normal hours of work."