But Mr Brown is understood to have accepted the word of Mr Whelan that he did not leak details about Mr Mandelson's personal loan from Geoffrey Robinson, the former Paymaster General.
Sources close to the Prime Minister say that it will be up to the Chancellor whether or not he keeps on his spin doctor, who is one of his closest personal aides. But Alastair Campbell, the Prime Minister's press secretary, is said to have urged that Mr Whelan go, to draw a line under the Mandelson affair.
Mr Whelan has been advised to tone down his flamboyant style, which involves drinking white wine spritzers with journalists in the press gallery bar.
Although he is usually to be found at the end of his mobile phone, Mr Whelan is, at present, "missing" and unavailable for comment. Scores of messages on his pager have not been answered.
Last week, Scotland's biggest selling daily newspaper, the Daily Record, printed a "wanted" poster offering a free flight to Mr Whelan's favourite Westminster pub, the Red Lion, for evidence of his whereabouts.
The spin doctor's critics believe that he may have played a part in the inclusion of Mr Mandelson's personal loan in a forthcoming biography of the former secretary of state. But the political journalist who wrote the book, Paul Routledge, has denied this.
Mr Whelan has had a key influence on the presentation of the Chancellor in the media. Within months of starting his job in 1993, the former student communist set about sprucing up Mr Brown's image. This included stage- managing an "exclusive" picture of Mr Brown and girlfriend, Sarah Macaulay, enjoying a romantic dinner together in a London restaurant, to quash rumours about the Chancellor's private life.
His influence over Mr Brown's image also surfaced during the Chancellor's 1997 Budget speech. Mr Whelan used a paper to warn Mr Brown that he had failed to deliver a satisfactory "soundbite" for television news bulletins.
Mr Brown duly repeated his comment - with more force - that VAT on fuel would be reduced. The incident led to a reprimand from Betty Boothroyd, the Speaker of the House.Reuse content