The Federal Treasury would lose the power to prepare the major economic forecasts that underpin the budget under a Labor government.

Shadow treasurer Chris Bowen will today outline a plan to give responsibility for forecasting inflation, unemployment, the terms of trade, as well as nominal and real GDP to the Parliamentary Budget Office (PBO).

The PBO was established by the last Labor government to provide independent budget and fiscal policy analysis.

It is also available to cost the policies of non-government parties ahead of elections.

Mr Bowen will tell the National Press Club that the Coalition's attempts to "circumvent the Charter of Budget Honesty" has been a spur to Labor considering new ways of providing transparent and independent forecasts.

He says the Abbott Government trashed the Charter, which was introduced by former treasurer Peter Costello and "recklessly politicised" its first budget update.

Mr Bowen will propose changing the PBO legislation to give it the power to prepare the macro-economic forecasts as well as the Intergenerational Report, which Treasury currently publishes every five years.

"A Government unafraid of accountability and transparency would not be afraid of outsourcing this forecasting in their budgets and economic statements," Mr Bowen will tell the Press Club.

He will argue that if the change is made, treasurers could "no longer interfere and influence macro-economic forecasts which are the key determinants of estimates of revenue and expenditure in Commonwealth budgets".

Labor is also proposing the PBO publish an annual report on whether the budget is in structural deficit or surplus.

It released analysis of the structural budget balance last year.

"Annual reports of the structural deficit may not always be convenient for governments," Mr Bowen will tell the Press Club.

"But the Australian people deserve to know the true state of the budget, free from spin and manipulation."

He will portray the move as strengthening the Charter of Budget Honesty and in line with world's best practice.

Labor will pledge to bring in the changes within 12 months of taking office.