Labour's 'triple lock': Robert Peston looks at the numbers in detail.
At the launch of the Labour Party's election manifesto on Monday, party leader Ed Miliband spoke about the so-called "triple lock" of responsibility.
He promised a balancing of the books, annual cuts to the deficit and a falling national debt.
Opponents, though, say the lock is not as secure as the Labour leader suggests.
Robert Peston looks at the numbers in more detail.