EMPLOYERS have warned that young workers will lose jobs if the shop assistants union succeeds in legal action to prevent students from being employed after school for shifts of a minimum 90 minutes.

The Federal Court will today start hearing a union challenge to a Fair Work Australia decision that eased a three-hour minimum shift requirement imposed on students working in after-school retail jobs.

The Shop Distributive and Allied Employees Association claims the full-bench ruling, if allowed to stand, has the potential to reduce the minimum-hour entitlements of 200,000 school students and casual employees across the country.

The National Retail Association said the case would “play a significant role in how the retail sector performed, after difficult conditions in recent years”.

“The decision reached by Fair Work Australia was in the best interests of employees, employers and the general public,” the association’s executive director, Gary Black, said.

“A successful appeal against the ruling to allow minimum 90-minute shifts for young workers will see the end of after-school jobs and hurt retailers, who will be forced to employ older workers.”

Mr Black said a successful union challenge would “rob school kids of a chance to participate in the workforce and negatively affect retailers such as newsagents and grocers who are only open until early evening”.

“Overturning FWA’s decision will inevitably result in young and vulnerable staff being laid off and denied work,” he said.

The union’s national secretary, Joe de Bruyn, accused employers of arguing for “cheap labour”. He said the employers were trying to replace the jobs of ordinary adult workers with less expensive younger employees.

Under the tribunal’s conditions, the 90-minute engagement will apply only if the employee is a full-time student, the hours worked are between 3pm and 6.30pm on a school day, and the employee and their parent or guardian agree on the shorter period.