Governments of both main stripes have raised tens of billions of pounds since the partial sale of the government’s holding in British Aerospace ushered in the era of really big privatisations more than 25 years ago. But few have generated the scale of controversy that has dogged the sale of Qinetiq.

Raising about £576m so far, it is a relative baby among disposals. Among those dwarfed by it, for example, are BNFL’s sale of Westinghouse for $5.4bn in 2006, the £2.3bn the government raised this June by selling part of its interest in British Energy, or the £5.4bn raised in 1986 from the sale of British Gas.