Climate change is shaping up as a key issue ahead of a federal by-election with Energy Minister Chris Bowen accusing the Liberals of being anti-business by not backing emissions reduction measures.

On the campaign trail alongside Labor candidate Mary Doyle, Mr Bowen accused the opposition of being anti-business for refusing to support emissions caps for the 215 biggest polluters.

Ms Doyle, a former unionist and finance worker, is up against barrister and Melbourne City councillor Roshena Campbell in the battle for the marginal seat of Aston.

Mr Bowen said he had positive discussions with Greens leader Adam Bandt and independent David Pocock on climate action but could not make headway with the Liberals.

“They don’t care about good policy,” Mr Bowen told reporters in Melbourne’s outer suburban seat of Aston on Friday.

“They’re against the national reconstruction fund, they’re against housing for victims of domestic violence, they’re against safeguards reforms and zero emissions come down – which industry wants and business wants.

“The president of the Business Council could not have been clearer this week, business wants to see the safeguards mechanism passed, Peter Dutton’s Liberal Party is the party of anti-business.”

Under the Albanese government’s proposed legislation, an emissions cap would be enforced, with companies breaching limits able to buy carbon offsets or trade emissions with other companies.

Companies would need to reduce emissions by 4.9 per cent every year until 2030.

Opposition energy spokesman Ted O’Brien previously said the plan was a Trojan horse for the carbon tax that Labor has longed for for many, many years.

The government will need the support of the Greens and at least two crossbenchers to pass the mechanism through parliament.

The government has said the safeguard is critical to meet its emissions reduction target of 43 per cent by 2030 and net-zero emissions by 2050.

The by-election is to replace outgoing federal Liberal MP Alan Tudge.

– AAP