The Chancellor is planning to pass a law later this year compelling all future governments to run a budget surplus in "normal" economic conditions, the FT reports. That means the state will not even be allowed to spend all the money it collects, but instead put some aside for the future.
Osborne will announce plans for his surplus law at the prestigious Mansion House event in the City of London tonight.
Osborne will say in his speech: "With our national debt unsustainably high, and with the uncertainty about what the world economy will throw at us in the coming years, we must now fix the roof while the sun is shining."
Few governments since the Second World War have managed to limit spending to as much as they collect, let alone run a surplus. George Osborne hasn't managed the feat since taking office in 2010, with the most recent estimate putting the spending deficit at 3.3% of GDP for this year. The government is currently committed to balancing its books by 2018.
The Office for Budget Responsibility, created by Osborne in 2010, will police the new rules and will have the power to relax the spending commitments in certain circumstances, for example if the country falls into a recession.