A controversy erupted in February when Carol Fisher, the chief executive of COI Communications, was given an extra role as the Government's chief adviser on marketing communications, in which she reports to Campbell. Lord Macdonald of Tradeston, the Cabinet Office minister, sought to defuse the row when the extension of Campbell's remit was raised in the House of Lords.
Lord McNally, a Liberal Democrat peer, said a political appointee was now the "last line of control in decisions on Government campaigns.
Macdonald replied: "Alastair Campbell will not be able to intervene in the COI. Carol Fisher, the chief executive, will continue to report to me."
He refined the Government's original statement in February by saying Fisher would be "working with Campbell, rather than "reporting to" him.
The minister hit back at criticism of the 70 per cent rise in Whitehall's annual ad budget before last year's general election in a Panorama programme on BBC television last month.