The bill for management consultancy within government is set to top £20bn over the lifetime of three parliaments, according to a former consultant who has carried out an extensive survey of public spending on external advice.

David Craig, formerly of Capgemini, the consulting company, and the author of Plundering the Public Sector, estimates that total expenditure on outside expertise will be worth £70bn from 1997 to 2009. This larger number includes spending on implementing large information technology projects, such as Connecting for Health, the digitisation of NHS records.