The shadow chancellor has said Labour will examine every line of public spending if it wins back power in 2015.
Ed Balls says the party would spend a year carrying out a "zero-based budgeting" exercise in an attempt to justify the budget and every penny the taxpayer spends.
He told The Guardian the plan is designed to show voters that the party understands the scale of the public spending challenge facing the country.
Mr Balls said the goal is to identify the cost of everything spent in every department and build a new budget from scratch instead of evolving existing spending plans.
The politician told the newspaper: "The public want to know that we are going to be ruthless and disciplined in how we go about public spending.
"For a Labour government in 2015, it is quite right, and the public I think would expect this, to have a proper zero-based spending review where we say we have to justify every penny and make sure we are spending in the right way."
Mr Balls said Labour should have committed to such a review in 1997. A similar move was rebuffed by Gordon Brown's Treasury in 2005.
But the shadow chancellor warned that Labour would not start completely from zero - insisting the party would be making some tax and spend commitments in its 2015 manifesto. He said items of spending would also be excluded from the review if cutting them would lead to higher costs in future.
He said: "We will need to make decisions in our manifesto on our big strategy on taxation and spending, as well as our fiscal rules. As in past parliaments, that could mean we make overall commitments on some items of spending.
"For example there is a cross-party consensus on spending on international development. But that does not mean the Department for International Development budget is taken out of the zero budget review - you still need to know the money is being spent wisely."