Ms Cass-Gottlieb said the current law enabled “strategic behaviour” by merger parties to avoid the ACCC’s scrutiny. “It actually means we are unable to perform the important role that a merger assessment does for the Australian economy,” she added.

Ms Cass-Gottlieb said, for global transactions, the competition regulator was reliant on remedies imposed by foreign anti-trust authorities, and these were not always “fit for purpose” for Australia’s unique market.

The lack of early access to mergers and acquisitions also extended to some deals involving two domestic parties, she said.

“In a time of such an uncertainty and such rapid change, the ACCC needs the time to move as early as possible to do a well-informed assessment. So we are commencing a process with government and discussing those questions,” she said.

Ms Cass-Gottlieb joined the ACCC as chairwoman in March 2022, after being widely recognised as one of the country’s top competition lawyers at Gilbert + Tobin.

While she was appointed by the Coalition, her interest in competition law reform is likely to carry weight with Labor Treasurer Jim Chalmers, who has spoken of the need to promote competition and valued her advice on a range of matters such as the gas market.

Whereas Ms Cass-Gottlieb’s flagging of potential merger law reform appears focused on the ACCC gaining earlier access to assess deals, her predecessor was more strident in calling for extra powers to block mergers and acquisitions.

The current legal test that the ACCC considers is whether a merger will have “the effect or likely effect of substantially lessening competition”.

Mr Sims, the previous ACCC chairman, has repeatedly called for tougher anti-merger laws, including to stop the big banks from buying emerging fintech competitors.

Mr Sims’ urging came after the ACCC under his leadership has lost several major court cases opposing mergers, including TPG Telecom-Vodafone Hutchison, Pacific National-Aurizon and AGL Energy-Macquarie Generation.

But in response to Mr Sims pleas, former ACCC chairman Graeme Samuel said the merger laws were not the problem, but rather the ACCC was picking the wrong cases to litigate or pursuing the wrong legal strategy.