The announcement came less than a week after Alastair Campbell, who has directed Blair's information operation since the government took office in 1997, announced he was resigning.

The shake-up effectively dilutes Campbell's power over two posts. A politically neutral civil servant, yet to be named, will be in charge of communicating government policy. Meanwhile, Downing Street's political operation will be headed by Blair's new director of communications, former Labour Party chief press officer David Hill.

The reform created a new post of senior official spokesman for the PM, a politically neutral position answerable to the civil servant in charge of government communications.

The structural changes to the communications unit are viewed as an effort to repair relations with the British media and bolster public confidence in the government. The shake-up effectively scales back the power held by Campbell and addresses concerns that the lines between politically appointed special advisers and impartial civil servants had become blurred.

The changes draw heavily on a review of government communications, carried out by senior journalists, media specialists and government advisers, and chaired by Bob Phillis, chief executive of Guardian Media Group, which owns The Guardian and The Observer.

Blair has frequently faced accusations that his Labour Party government is more concerned with presentation of policies than with substance.

''I think the government absolutely knows that it has to kill off the curse of spin once and for all and it is determined to do it and will set in place structures that are designed to achieve that end,'' said Labour lawmaker Tony Wright, chairman of the Public Administration Select Committee.