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Let ye among us who has not found £27bn down the back of the sofa cast the first stone. That'd be almost all of us.

Last November, George Osborne managed to deliver a series of popular giveaways thanks to optimistic economic forecasts from the Office for Budget Responsibility, who are responsible for predicting economic growth.

Because they said the UK would grow quickly, they said Osborne wouldn't need to make so many cuts, as growth boosts tax revenue. This was used to slow the pace of cuts, boost personal allowances, and to introduce the living wage.

But what the OBR give, they can take away. They're less optimistic now – much less optimistic – and so suddenly Osborne has lost £56bn. Oops. The rest of this year's budget was Osborne trying to make up this lost cash, ideally without us noticing too much. Unfortunately for him, the IFS noticed.