Australia’s major supermarkets should face hefty fines if they do not comply with an industry code of conduct when dealing with suppliers, a government-commissioned report said while rejecting calls to give regulators the power to break up the big chains.

“The existing Food and Grocery Code of Conduct is not effective. It contains no penalties for breaches and supermarkets can opt out of important provisions by overriding them in their grocery supply agreements. I firmly recommend the Code be made mandatory,” Emerson said in the report.

Companies should be fined up to A$10 million or 10% of revenue if they do not comply with the code, according to the report. The final report is due in June. Woolworths and Coles booked sales of A$64 billion and A$41 billion in 2023.

The two biggest grocers in Australia ring up two-thirds of the country’s grocery sales between them, prompting calls from growers and opposition leaders to break up the supermarket giants to improve competition and prices.