Bill Shorten says “fee-gouging” bank-owned superannuation providers will be targeted, if his proposed royal commission goes ahead.

The Labor opposition has been pushing for a royal commission into Australia scandal-plagued banking sector since at least 2016, but with no interest coming from the Federal Government, the idea will most likely wait to become an election issue in the next cycle.

Early estimates suggest the big banking probe would take about two years and cost close to $53 million, considerably more than the Royal Commission into Trade Union Governance and Corruption, which cost around $46 million.

But the opposition leader says it would be money well spent.

“We’ve tried just about everything else,” Mr Shorten has told Investment Magazine.

“A royal commission is the king of all inquiries. It has the power to look behind…there are basically no excuses you can give not to give evidence. It has very strong powers.”

He said those powers would be needed to fight back against a pathological lack of accountability in the banking sector and the financial services industry.

“Too many problems occur too often,” Mr Shorten said.

“And every time it does, we all get the mea culpas and they say it won’t happen again, until the next time.”

He said the superannuation sector would be in the crosshairs.

“We haven’t finalised the terms of reference, so I wouldn’t want to say a particular issue in superannuation is a particular focus,” Mr Shorten said.

“But we’ll look at case studies where there have been problems across financial services and banking.”

“I can’t think of any other sector of the Australian economy that represents literally hundreds of billions of dollars where the government wages such an ideological war.

“But industry funds, I think, are good competition for banks in superannuation: low fees, good performance.”

Mr Shorten said he wanted to restore choice in superannuation.

“If something is not performing, you should be allowed to pull out,” he said.

“But choice is getting undermined, quite often, by life insurance products now. People reach a certain age and all of a sudden they’re stuck in a bank fund because they can’t get a comparable life insurance policy in another fund, but they keep getting gouged on fees.”

The Labor leader also highlighted the gender gap in superannuation as a significant issue.

Reports by Association of Superannuation Funds of Australia (ASFA) show that in 2013-14, the average superannuation account balance for a man was $98,500, but for women it was less than $55,000.

“It’s a big issue…we’re working on our policies there. We see it as a gap in the current system,” Mr Shorten said.

“Women lose their super when they go on parental leave. The pay gap is real. In the public service, it’s 8.6 per cent; across Australia it’s nearly 20 per cent. Women, on average, have much lower account balances. Paying women equally to men would be a good start, because then the 9.5 per cent would be the same for everybody. Get more women into positions of power.”