Figures released alongside last week’s Budget show that the Treasury has had to revise sharply upwards its official forecast for spending on benefits, even though the previous estimate was only made at the Autumn Statement in December.

Figures show the forecast spend on benefits and tax credits in the five years between 2011/2 and 2015/16 has now jumped by £6.4billion since December 5.

It means that every day since Chancellor George Osborne delivered his Autumn Statement, the projected benefits bill has risen by £61million.

The revised figures mean that Mr Osborne is now on course to spend £20billion more on benefits than he had expected at the start of the Coalition.