The mid-year budget update, due by the end of next week, is expected to show a worsening in the state's finances, due to an $80 million hit to GST revenues and extra spending commitments made by Labor since the May budget.

Mr Hodgman said yesterday that the already-announced $507 million savings in the Liberals' May alternative budget would guarantee the state was economically better off under a Liberal government than under Labor.

"All our savings have been announced," Mr Hodgman said.

The bulk of the Liberals' savings come from ripping $95 million out of Forestry Tasmania and cutting 500 public service positions over two years.

The Liberals will also claw back $18.5 million a year from supplies, consumables and consultants, but they are yet to provide details.

But with no new savings measures and $370 million in spending commitments, the Liberals' promise to deliver a $35 million surplus in 2015-16, a year ahead of the government's projected $9 million surplus, is on shaky ground.

Mr Hodgman acknowledged yesterday the worsening budget situation might delay the surplus, but he criticised Labor for making $50 million of spending commitments since the May budget without identifying any savings.

The government has repeatedly criticised the Liberals' big- spending promises and questioned its savings strategy.

"For too long the Liberal Party have got away with dodgy costings, false savings and a complete lack of detail on how they will deliver their promises," Premier Lara Giddings said.

"There are only three ways Will Hodgman can possibly deliver his extravagant spending promises: going into debt, slashing jobs or selling assets. At the rate Will Hodgman is spending, he will probably have to do all three."

Mr Hodgman also called on the government to release the budget update immediately.

"It's overdue and Tasmanians should see the true state of Tasmania's finances," he said.