Lobby groups on either side of the ‘effects test’ debate will be keen to have their voices heard by Australia’s new prime minister, after the issue came to the fore in parliament.

PM, Malcolm Turnbull, has flagged a further cabinet discussion on the so-called effects test for business.

The law change would curb the domination of big business and effectively lower the threshold for proof in anti-competition cases.

Asked by shadow treasurer, Chris Bowen, whether The Nationals had been promised the law change as part of the new coalition agreement, Turnbull told parliament it would be a “decision of the cabinet”.

The measure was raised with Turnbull by Nationals leader, Warren Truss, as part of their discussions about a new coalition agreement.

Coalition partners, The Nationals, support the introduction of an effects test, with three Nationals crossing the floor of the Senate on Tuesday to vote against the government.

Bridget McKenzie, John Williams and Matt Canavan backed a Greens motion calling for an effects test on market power to be included in competition policy.

The introduction of an effects test was recommended by the Harper Review released in March.

Big retailers, such as Coles and Woolworths, have opposed any change, while the Council of Small Business of Australia is calling for its introduction.