The ACT budget’s net operating balance has declined to a $381.1 million deficit, according to a pre-election budget update for the territory.

The update, prepared by Treasury, takes into account all known decisions of the government up to the beginning of the Caretaker period.

While the update showed the territory’s financial performance remains within the boundaries outlined in the budget fiscal strategy and budget plan, the outlook for the headline net operating balance for 2012-13 declined to a deficit of $381.1 million since the publication of the budget.

Treasury believe this is largely due to the fall in the discount rate used to value superannuation liabilities at June 30.

The Canberra Liberals said the figures showed “the biggest deficit in Territory history”.

“Four years ago, almost to the day, Jon Stanhope promised ACT Labor would ‘not take the budget into deficit in any year,’” Shadow Treasurer Brendan Smyth said.

“This is a government which can’t be trusted to manage the ACT economy or tell the truth about numbers.”

Treasury says the ACT’s share of GST is likely to increase across the forward estimates, based on preliminary estimates of population from the Australian Bureau of Statistics.