Abbott under pressure on competition law

Tony Abbott is under pressure from coalition MPs to push ahead with a test to stop big retailers dominating the market to better serve the interests of consumers and smaller operators.

The prime minister last week announced he had deferred a decision on the so-called "effects test" which would lower the threshold for proof in cases of perceived anti-competition.

Small Business Minister Bruce Billson has been pushing hard for the reform, which was recommended by the Harper competition review, but it's been resisted by Treasurer Joe Hockey and other senior colleagues.

At a joint coalition meeting in Canberra on Tuesday, nine coalition MPs spoke on the issue with most supporting Mr Billson's position.

It's understood most of the Nationals MPs in the room were also supportive.

Mr Abbott told the meeting small business reform was important, but he cautioned MPs not to take a "theological view" on the recommendations of the Harper review.

Mr Billson told Radio 2GB on Monday he had not been "rolled" on the issue.

The government was working "in a very thoughtful way" through all 56 of the Harper recommendations and the cabinet discussion was "part heard".

He said the consumer interest is not served by big retailers dominating the market.

Labor MPs had also queried shadow treasurer Chris Bowen over his opposition to an effects test.

They said the competition test could be useful in limiting the market power of Coles and Woolworths.