The Morrison government has accused a left-leaning think tank of wanting to take money out of people’s pockets for opposing personal income taxes.

The government has flagged it is considering bringing forward personal income tax cuts scheduled for 2022 and 2024 in the October 6 budget.

But an ad campaign produced by the Australia Institute, backed by 40 prominent Australians – including two former Reserve Bank officials, a former Liberal Party leader and the head of the welfare lobby group ACOSS – says they won’t provide the stimulus economy needs.

“At a time of recession, the Australia Institute wants to take money out of people’s pockets,” a government spokesman said.

“We’re always focused on how we can give it back to them and lower taxes. The Australia Institute and the Labor Party have never met a tax increase they didn’t like.”

Institute research released in recent weeks suggests the cuts will benefit high income earners, who are more likely to save rather than spend the extra cash.

“We’ll need substantial stimulus for an extended period,” former Reserve Bank deputy governor Stephen Grenville says.

“Cutting top-rate income tax would be a weak stimulus which undermines the equitable and progressive tax structure we’ll need when the COVID crisis is over.”

Former federal Liberal leader John Hewson said the Coalition naively believed tax cuts were good politics.

“But they won’t be as they increase inequality and fail to ensure job security and increasing wages with our economy still struggling to exit recession,” Dr Hewson said.

Former Liberal leader John Hewson is among those to criticise the tax cut plan.

A tax expert also said Treasurer Josh Frydenberg would get more bang from taxpayers’ bucks by targeting business initiatives.

BDO tax partner Mark Molesworth said personal tax cuts alone would not be enough to drive a worthwhile stimulus response in the face of the first recession since the early 1990s.

“More Australians are being frugal with their money so a tax cut will not inspire a spending spree even with Christmas approaching,” Mr Molesworth said on Monday.

“To encourage consumer spending, it would be better to look at business investment incentives.”

These could take the form of an investment allowance, which would provide an incentive to buy assets and expand business operations.

He also suggested an employee headcount rebate, which would be paid as a tax benefit in cash per new full-time employee created by a business.

Cabinet minister David Littleproud declined to comment directly on whether the government was considering incentives for businesses to take on more staff, saying Mr Frydenberg would “reveal all” when he hands down the October 6 budget.

“The Treasurer will want to have a big bang on election night,” he told the Nine Network on Monday.

Social Services Minister Anne Ruston, who gave an update on the federal government’s plans to cut JobKeeper payments within days, also refused to be drawn on what might be in the looming budget.

“Clearly matters for the budget are not something I am going to speculate on here today,” she said.

“Certainly the budget will be very focused on getting the economy opened up and getting people back to work.”

-with AAP