Labor promises 10-year costing of policies before election

Shadow treasurer Chris Bowen says Labor will reveal how much its policies will cost over the next decade closer to the July 2 federal election.

Chris Bowen is promising Labor will release four and 10-year costings of its policies. (AAP)

The ritual election costings debate has begun with shadow treasurer Chris Bowen promising Labor will release four and 10-year costings of its policies.

But the bottom line won't be revealed until the latter part of the campaign, "after we've announced the last bulk of our policies", Mr Bowen told the National Press Club on Tuesday.

"That will enable us to say more about the trajectory back to budget balance," he said.

Labor would stick with the independent Parliamentary Budget Office for its costings, rather than submitting policies to Treasury, Mr Bowen said.

"They are well resourced, competent people and if there is a dispute between the Treasury and the Parliamentary Budget Office as to costings, that does not automatically mean that the PBO is in some way in error," he said.

Mr Bowen also said while Treasury was an arm of the government, its secretary was not a political play thing and he would work with the Abbott-appointed head John Fraser.