The treasurer told a forum on Thursday the coalition has already delivered a five percentage point reduction in taxes for businesses with a turnover of up to $50 million.

"It remains our mission to extend those tax cuts to all businesses across the economy, to give them the incentive to invest, hire more Australians and create a stronger economy," Mr Morrison told the Australian Business Economists forum in Sydney.

The Senate economics committee on Thursday continued its inquiry into claims made in a letter to all senators from the Business Council of Australia and 10 corporate members stating a tax reduction would deliver jobs, investment and economic growth.

BHP chief financial officer Peter Beaven told the committee that if the corporate tax rate was reduced, inevitably "Australian assets would win investment".

"The link is plain and simple as our commitment," he said.

He said it would deliver billions of dollars more in wages, payments to suppliers and returns for BHP shareholders.

At that point, the hearing in Melbourne was shut down by former Esso workers shouting claims of pay rises were "absolute garbage".

Liberal senator Jane Hume described the interruption as quite intimidating with "big burly men" threatening witness and senators.

Once order was restored, Energy Australia chief financial officer Alastair McKeown told the hearing lower taxes would improve the economics to get many of its new energy projects up and running "which is what the country badly needs".

But ACTU national campaign coordinator Lance McCallum argued the reductions won't increase wages and just give bigger profits to foreign companies operating in Australia.

"Why on earth would anyone seriously believe a tepid and vague statement from the BCA saying business will invest more, which in turn might lead to higher wages," he said.

"Frankly, we are surprised they have the gall to ask."

The government fell short of getting sufficient numbers in the Senate before Easter to pass the legislation to reduce the company tax rate to 25 per cent from 30 per cent for all businesses.

Crossbenchers Tim Storer and Derryn Hinch remain opposed to the package, while One Nation's Pauline Hanson wants any tax cut for banks quarantined for compensation for victims of misconduct.

Senators Rex Patrick and Stirling Griff of the Centre Alliance, formerly known as the Nick Xenophon Team, are still doing "due diligence" on the tax cut, despite initially opposing the plan.

During the Q&A session following his speech, Mr Morrison dismissed the suggestion it was a myth that tax cuts won't fuel investment.

"What makes people think that taxing businesses more will make them do better?" he responded.

"We fundamentally believe this as a principle and that is that Australians and Australian businesses know better how to spend their money than any government does, than any academic or any economist does, even than any politician does."

Australian Associated Press