Government departments blew their 2013-14 budget by $90 million, up from $60 million last year.

The Liberals seized power from Labor in March after 16 years in Opposition, and the cost of the changeover, including moving offices and a thorough clean up, added $4.7 million to the overrun.

Extra unbudgeted costs included $150,000 in payroll tax relief for Serco's 50 extra call centre jobs in Burnie, and $710,000 for the Tall Ships festival and Dark MOFO.

Treasurer Peter Gutwein said he was advised that the Dark MOFO festival's funding allocation was insufficient and required more than $500,000 extra.

The festival organisers cancelled the Launceston program, saying they would need $1 million to get it up and running.

Mr Gutwein said his approach to the discretionary funds was "very, very careful" and the vast majority of the $90 million in extra funds covered spending from the former government.

Legislation to free up funds to tide the state over until the state budget is handed down on August 28 was also debated in the lower house yesterday.

The bill sought parliamentary approval for $1.5 billion to fund agencies so that the government can continue everyday expenditure, such as the running of schools and hospitals.

Future savings aren't included in the bill, and the late budget could delay the Liberals' ambitious savings quest to rein in spending by $500 million over the forward estimates.

Opposition Leader Bryan Green said the government had "irresponsibly delayed" the budget until August.

"You've got more furrows on the brow since the federal budget," Mr Green said.

Mr Gutwein said it made "perfect sense" to have the budget in August.

"This is an opportunity to take into account the federal budget," Mr Gutwein said.

Another change to take immediate effect from the start of the new financial year is the scrapping of taxpayer support for Forestry Tasmania.