His successor as press secretary was Sir Gus O'Donnell, who went on to become cabinet secretary and head of the civil service in 2005.

Sir Gus O'Donnell, head of the civil service, said she was a role model to all civil servants and he accepted her decision with "huge sadness".

Sir Gus O'Donnell has served this country with distinction.

A key priority for both of us will be to take forward much of the great work set up by Sir Gus O'Donnell.

I am copying this letter to Cabinet colleagues and to Sir Gus O'Donnell.

Labour have called for an inquiry, and so they should wait until Sir Gus O'Donnell has finished his investigation.

I am copying this letter to Sir Gus O'Donnell.

Sir Gus O'Donnell, the Cabinet Secretary, will now take control of the inquiry.

Sir Gus O'Donnell led the way by publishing his business expenses first.

He asked Sir Gus O'Donnell, the cabinet secretary, to look at this.