By Anhar Khanbhai

The battle between employers and their employees has turned ugly, as employers expand their push to cut minimum working hours.

According to submissions to a major review of the awards system being conducted by Fair Work Australia, employers want to slash weekend pay for casuals.

They are also calling for the end to evening penalty rates and to narrow the definition of ''shift work'' demanding as little as 90 minutes a day for school students.

After analysing more than 200 submissions to the review, unions have accused employers of ''merely laying the foundation'' for an Abbott government to cut wages and conditions.

''What employer groups want is a 24-hour, seven-day-a-week economy in which they have all the flexibility, the power and control over who works when and how little they are paid,'' ACTU secretary Jeff Lawrence said.

However, employer groups say the push to reduce entitlements for some workers is a consequence of the Rudd and Gillard governments allowing costs to skyrocket for businesses from 2009.

The ACTU played on a submission from the National Retail Association arguing in favour of reduced minimum hours for secondary school students employed as casuals.

The retail group wants a Fair Work Australia decision last year for a 90-minute-a-day minimum for students to be expanded into other retail awards.

Employer submissions included new annualised salary arrangements that would avoid payment of allowances, penalties and overtime, a narrowing of the definition of shift work to reduce access to pay and leave entitlements and discounted rates for apprentices and trainees where adult rates have traditionally applied

Lawrence said the submissions showed employers wanted a return to the former WorkChoices policies of the Coalition.

''Australia's employer groups have never accepted the reality that WorkChoices-style laws were whole-heartedly rejected,'' Lawrence said.