Labour will try to improve its reputation for financial competance this week with a Commons vote demanding all parties' manifestos are independently audited.
Ed Balls is calling for the Office of Budget Responsibility (OBR) – the office set up by George Osborne to double-check the figures in the Budget – to scrutinise spending and tax commitments made by the main parties at the next election.
"I want every spending and tax measure in Labour's manifesto to be independently audited by the Office for Budget Responsibility," the shadow chancellor said.
"And I believe the Tories and Lib Dems should be willing to subject their manifestos to independent scrutiny too."
George Osborne once suggested he might support the move but has turned against it in recent years.
The chancellor may be wary of offering Labour a stamp of economic legitimacy ahead of an election in which he plans to paint them as financially irresponsible.
"To give the OBR the legal power to do this before the next election we need cross-party support for my proposal," Balls said.
"This policy has already won the support of some Conservative and Lib Dem MPs. George Osborne used to say he was interested in this idea. But now that the election is approaching he seems to be resisting it."
Conservative chair of the Treasury committee Andrew Tyrie has already backed the move, saying it would "enhance the quality of public debate on tax and spend".
Chairman of the OBR Robert Chote was also supportive, saying it would "contribute to better policy making, to a more informed public debate, and could help facilitate coalition formation when party programmes need to be reconciled".
The vote would come after an opposition day debate in the Commons on Wednesday.