The South Australian State budget - unveiled late yesterday - contained a surprise, succinctly explained by Martin North of Digital Finance Analytics in his blog as a plan that will see South Australia's treasury "charge a 0.015 per cent levy on the major banks' bank bonds and deposits over A$250,000 but will exclude mortgages and ordinary household deposits."The tax, to be introduced from 1 July 2017, is expected to raise $370 million over four years.It represents SA's estimated share of bank liabilities subject to the Commonwealth's quarterly levy.SA Treasurer Tom Koutsantonis was unapologetic in targeting the banks, claiming they had been serving the interests of their shareholders at the unfair expense of customers for years."In the last year alone, the five banks have collectively made profits of about $30 billion after tax," he said.Now the risk is that other states follow suit, North suggests in his blog."The banks are an easy target, profitable and unpopular; but we need to be aware of the unintended consequences of this move," he says. "Once again it is likely the costs will be passed on the bank customers, as the tax will lift the banks' treasury costs, so this becomes a further indirect tax on consumers, just rather well hidden. And 'convenient'."The banks and big business lobby groups were fast and furious with their responses to news of another bank tax.Australian Bankers Association chief executive Anna Bligh called the move "an outrageous cash grab without policy substance.""Furthermore, when the GST was introduced, a range of state taxes were eliminated, including some state taxes relating to financial institutions. Today's announcement is a step back in time."Tax policy in Australia is now becoming a joke at the whim of political opportunism and South Australia is trying to impose triple dipping for bank taxation," Bligh said.ANZ chief executive officer Shayne Elliott called it a "deeply concerning tax" and suggested it would impact business investment in South Australia at a time when its economy is struggling with low growth, low business confidence and high unemployment. "The comments attributed to the State Treasurer show a clear lack of understanding of the role banking plays in supporting the South Australian economy and the damage that opportunistic and ill-considered cash grabs will have on the long term economic prospects of the State," Elliott said.NAB called the announcement by the SA Government "poor policy without logic"."The role of the Australian banks is to support customers and communities and drive economic growth and activity. It is not to be a blank cheque so governments can cover their own budget shortfalls," NAB added, a theme picked up by the Business Council of Australia."South Australia's new bank levy exposes the desperation of a government that is unable to get its own budget and spending under control," Business Council chief executive Jennifer Westacott said.After issuing a statement berating the South Australian Government for destroying jobs and investment with the newly created bank levy, Westacott moved up a level: "The Turnbull government must bear responsibility for letting