Government figures showing that the costs of bureaucracy have fallen since 1997 have been "fiddled", the Conservatives have said.

Shadow chancellor Oliver Letwin said £1 billion had been slashed from the figures by excluding the costs of devolved administrations in Scotland, Wales and Northern Ireland.

"This outrageous statistical fiddle is all too typical of a Labour government which specialises in using smoke and mirrors to hide its failures," Letwin added.