(Reuters) -Woolworths and Coles Group said on Friday they would defend class action proceedings commenced by a law firm in Australia's federal court over the grocers' alleged misleading discount claims.

On Thursday, Gerard Malouf & Partners launched a lawsuit against the country's top two supermarkets, Woolworths and Coles, accusing the duo of promoting misleading discount claims on daily-use products.

Earlier in September, Australia's consumer watchdog took the supermarket chains to court over "illusory" discounts, claiming that the firms had benefitted from revenue derived from the affected millions of units of products.

The country's incumbent prime minister, Anthony Albanese, who has faced pressure to do more to combat rising grocery prices and who goes to an election within a year, said the actions alleged by the regulator would be unacceptable if true.

Gerard Malouf & Partners, however, clarified that its lawsuit was different from that of the Australian Competition and Consumer Commission (ACCC), as the former is seeking refunds for the affected customers.

The consumer protection law firm said its suit had been launched to retrieve the price difference consumers had to fork out between the advertised 'discounted' prices and the real prices for hundreds of commonly purchased products at Coles between February 2022 and May 2023, and at Woolworths between September 2021 and May 2023.

"We estimate that the average Australian consumer could be eligible for a refund ranging between A$200 and A$1,300 +, depending on their shopping habits and purchases at these retailers," the law firm's chairman, Gerard Malouf, said in a statement on Thursday.

The law firm alleged that everyday items at both the companies had been subject to price hikes and the discounted prices were either higher or same as the price before the increase.