Australia faces more than decade of uninterrupted deficits according to an updated assessment by the independent Parliamentary Budget Office that shows Senate intransigence will carve a $100 billion black hole out of revenue between now and 2025-26.

Savings not realised as a result of parliamentary gridlock suggest the budget prediction of a near fiscal balance by 2018-19 is overly optimistic because it is based on budget repair initiatives that have not been legislated and, in many cases, are unlikely to ever pass the Parliament.

Treasurer Joe Hockey during question time at Parliament House in Canberra on Tuesday. Credit:Andrew Meares

The PBO's assessment lists out the proposals such as welfare cuts and major higher education reforms already factored into the current budget projections as savings but which are not yet approved, in a table entitled "unlegislated measures carried forward from the 2014-15 budget".

The finding means Treasurer Joe Hockey's lower-than-expected deficit estimate of $35.1 billion for the coming financial year may already be out of date. Without a legislative breakthrough, and leaving aside other variables such as a further decline in revenue from iron ore, company tax, and personal taxes, that 2015-16 deficit jumps from the $35.1 billion stated just a fortnight ago to $38.3 billion thanks to the cumulative impact of un-passed savings measures over the next 13 months.