As well as writing to those named in the e-mails, Mr Brown sent a letter to Cabinet Secretary Sir Gus O'Donnell, saying he was ready to take "whatever action is required" to prevent a repeat of the incident.
Although Stephen Byers, the former transport minister, is more obviously in the shareholders' sights, e-mail exchanges within government show that the Treasury, represented by one of Mr Brown's closest advisers, Shriti Vadera, was in the driving seat.
On Monday Health Secretary Alan Johnson said Mr Brown had had nothing to do with the e-mails and could not be held responsible for the actions of every person who worked for him.