The South Australian Labor government's plans to enact a secondary levy on select bank liabilities may tank in the upper house of the state's parliament after the South Australian parliamentary Liberal Party resolved to block the tax. Liberal leader Steven Marshall labelled the levy a "toxic new tax". With the opposition offside, Labor lack votes in the Legislative Council to pass the levy into law as the handful of cross-bench MLCs have voiced their antagonism to the bill.Proposed in the state budget two weeks ago, the levy replicated the new tax imposed at a federal level from this month.Tom Koutsantonis, the SA treasurer, said the Government will continue to promote its budget through the parliament in its current form.