Several unions in the Finance sector raised concerns regarding a planned class action against banks for allegedly charging Australians for more than $5 million in bank fees for more than 6 years.

Leo Carter, a spokesperson of the Finance Sector Union said the lawsuit may positively put an end to the issue of bank fees, though he is worried about the after effects.

"Our concern is that if this lawsuit is successful, the banks will simply make their money up somewhere else or, even worse, sack staff to recoup any costs," he said.

Mr. Carter suggested that a better regulation should be the solution to end this problem.

However, Bernard Murphy, a representative of Maurice Blackburn Lawyers, argued that something has to be done.

"There's no doubt that we have a good argument. Whether it will be successful, that's a matter probably for the High Court," he said.

Half a million Australians are expected to join the class action against local and foreign banks for repayments of dishonour and late fees.

James Middleweek, managing director of Financial Redress said the lawsuit may amount up to $5 billion, however, it depends on how many people will take part on the claims.

"Realistically if we got 300,000, 400,000 people to sign up over the course of the next few weeks and months we'd have a sort of 600, 700, 800 million [dollar] class action," he said.

As of press time, a total of 3,000 citizens registered at Maurice Blackburn Lawyers for a class action lawsuit.

Mr. Murphy, who also heads the lawsuit, said his company so far has the largest class action in the State.

Christopher Zinn, a member of the consumer group Choice, said there will be a strong public interest in the lawsuit. He also signed up for the class action as a private individual due to "an important legal issue to be tested."

"We would imagine that there is real appetite for remedy on behalf of the public," he said.