Retailers will push for their staff's hourly pay to be cut by as much as $8 an hour on Sundays.
Associations and organisations representing most of the nation's big and small retailers will tell Fair Work Australia that penalty rates - extra money paid to workers usually in recognition of the unsociable hours they work - should be reduced or cut altogether.
It follows unions last week arguing pay rates and penalties must be protected.
The National Retail Association, which is among the employer groups to appear at Fair Work Australia on Tuesday and Wednesday, says the penalty rates shop workers get are more suited to the Australia of the 1960s, when almost half the nation worked in production industries and few worked weekend shifts.
''Typical manufacturing working arrangements … generally involved a Monday to Friday working week,'' the association said in a submission to Fair Work Australia.
Retail workers get paid double-time on Sundays, and the association says this should be cut to time-and-a-half.
The association says penalty rates for those who work past 6pm on weekdays should also go. Another body, the Australian Retail Association, says that extra pay on Saturdays should also be abolished.
Bianca Seeto, deputy chief executive of the National Retail Association, said there was also a need for part-time provisions under the current laws to be changed, because they led many employers to only hire casual staff instead of permanent part-timers.
Joe de Bruyn, national secretary of the Shop Distributive and Allied Employees Association (SDA), said there had been ''wave after wave'' of employers trying to erode conditions for retail workers. ''Employers say that people want to work evenings and weekends. They say people would still work evenings and weekends if the penalties were lower. But who have they asked? Certainly not their employees,'' he said.
Emma Amies, a 19-year-old design student who works weekends at an independent supermarket, said the extra pay she got for working Saturday and Sundays was reasonable compensation for her not being able to go to events. ''If those penalties didn't exist, I would have to get a second job,'' she said.
The SDA last week presented evidence from Melbourne University academic Dan Woodman, who over seven years has tracked the lives of young Australians after they finish high school. The union said his research contradicted employers' claims that because some young people sought to work at weekends and nights there was no justification for penalties.
Dr Woodman found that young people who chose those hours suffered because their shifts regularly prevented them spending time with family and friends, and taking part in community and sporting interests.