Just a few days after the country's government passed its controversial tax levy bill on Australia's biggest banks, the state of South Australia has now twisted the thumbscrews even tighter.

The country's five largest banks are now entangled in a new tax brawl, after South Australia's (SA) government infuriated banks by imposing a new levy on the financial giants it said were «significantly undertaxed.»

The SA government announced a shock levy that is forecast to raise $370 million over the next four years from Commonwealth Bank, National Australia Bank, (NAB) Westpac, ANZ Bank and Macquarie.

Banks Fire Back

ANZ Chief Executive Officer Shayne Elliott wasted no time in responding to the South Australian Government’s announcement of a new state-based bank tax.

«This deeply concerning tax will likely impact business investment in South Australia at a time when its economy is struggling with low growth, low business confidence and high unemployment,» Elliott said.

He was quickly followed by an NAB spokesman calling the tax «poor policy without logic», and Westpac who calling the tax a «disgrace.»