Bigger fines will stop companies and individuals treating anti-competitive penalties as a cost of doing business and act as an actual deterrent, assistant minister for competition Andrew Leigh says.

Dr Leigh said a competitive business environment helped keep prices low for consumers.

"But we only get increased competition if the big companies play by the rules," he said.

"That's why Labor is increasing penalties, to ensure that there's a level playing field for all Australian businesses, big and small."

Under the bill, introduced to parliament on Wednesday, businesses will be slapped with fines of up to $50 million or 30 per cent of turnover for the offending period if they are caught engaging in anti-competitive behaviour.

At the moment, the maximum penalty is $10 million or 10 per cent of annual turnover - whichever is more.

Penalties for individuals will increase from $500,000 to $2.5 million.

Australia has comparatively light-touch penalties for anti-competitive behaviour among the OECD countries.

Erin Turner, head of consumer advocacy organisation CHOICE, says Australian companies are hit with an average penalty of $25.4 million when they break competition law compared to an average penalty of $320.4 million in similar countries.

"When our regulators are taking cases against large and powerful companies, like Google or Meta, they need penalties appropriate for that work," Ms Turner said.

Ms Turner supported the proposed legislation but said it didn't go far enough.

"In some cases when a business breaks the law, all regulators and courts can do is ask them to fix the problem," she said.

"No penalties apply when a business uses an unfair contract term or fails to offer a fair fix like a refund or repair when something breaks."

She said all protections in the Australian Consumer Law should have penalties attached.

Australian Associated Press