The Australian Competition and Consumer Commission (ACCC) said supermarkets and wholesalers that earned over AU$5 billion in the previous financial year must comply with the new mandatory Food and Grocery Code of Conduct, effective Tuesday, according to a Tuesday statement by the regulator.

The code requires written supply agreements and acting in good faith, the regulator said. It also protects suppliers from retaliation for exercising their rights.

The ACCC can enforce the code through infringement notices and court actions, with fines reaching up to AU$10 million or 10% of turnover, per the statement.

In response to MT Newswires' request for comment, Woolworths (ASX:WOW) reiterated its stance from last month supporting the code becoming mandatory.

Coles (ASX:COL) did not immediately respond to MT Newswires' request for comment.