Although an NAO spokeswoman said last night that an investigation was standard in large-scale privatisations, the opposition party was claiming a victory in its campaign to expose what it sees as a "shambolic" sell- off.
The sale of HMSO to a company called Electra Fleming for pounds 54m has been repeatedly attacked by the Labour Party.
A Commons motion put down by the frontbencher Brian Wilson said it was "hopelessly tainted and against the public interest. It added that Robert Fleming, one of the firm's directors, had given pounds 527,000 to the Conservative Party and that the Electra Investment Trust, with the former cabinet minister Tom King and the Tory peer Lord Vinson as board members, had "chipped in at least pounds 40,000".
Last night, Derek Foster, shadow Chancellor of the Duchy of Lancaster, said: "I am delighted that the NAO has responded to my calls for a thorough investigation into the shambolic sale of the stationery office. We totally opposed this crass privatisation from the outset. The knock-down sale of the office for less than a third of its market value was a complete disgrace and I trust the NAO will probe all aspects of this murky deal."
An NAO spokeswoman said: "We have made a decision that we are going to do a report on the HMSO, but it is standard." The investigation was just one of a number carried out after major privatisations, she added.Reuse content