A future Labour government will get the UK's finances back in the black as soon as possible, Ed Balls will say today.
The shadow chancellor will commit his party to creating a Budget surplus within at least five years, if not sooner, in a speech to the Fabian Society.
How quickly this is achieved will depend on the state of the economy and the public finances, he will say, but Labour "cannot and will not duck the hard choices".
These will include looking at new ways of delivering "public services suited to tougher times", he will add.
The speech comes at a crucial point in the economic debate between Labour and the Coalition.
Labour is facing calls to move on from its warnings of a cost of living "crisis" and respond to signs of an upturn in the economy.
Bank of England Governor Mark Carney has signalled he would ditch plans to consider an interest rates rise once unemployment rates hit 7%, in part because the economy is now due to hit that mark months sooner than predicted.
Mr Carney also cautioned yesterday that the UK economy remains well short of achieving "escape velocity".
Mr Balls will say: "I am today announcing a binding fiscal commitment. The next Labour government will balance the books and deliver a surplus on the current budget and falling national debt in the next Parliament. So my message to my party and the country is this: where this government has failed, we will finish the job.
"We will abolish the discredited idea of rolling five year targets and legislate for our tough fiscal rules within 12 months of the general election.
Tough fiscal rules which will be independently audited by the Office for Budget Responsibility.
"We will get the current budget into surplus as soon as possible in the next Parliament. How fast we can go will depend on the state of the economy and public finances we inherit.
"And because we will need an iron commitment to fiscal discipline, I have also asked the Office for Budget Responsibility to independently audit the costing of every individual spending and tax measure in Labour's manifesto."