“..Sir Gus O’Donnell, the cabinet secretary, became so alarmed by the prime minister’s behaviour that he launched his own investigations when he received reports of Brown’s bullying of staff. O’Donnell then gave the prime minister a stern “pep talk” and ordered him to change his behaviour. “This is no way to get things done,” he told Brown. The revelation that the prime minister’s behaviour was so extreme that it triggered a warning from Whitehall’s most powerful official will shock the political world and is bound to lead to claims from his opponents that he is not fit for another five years in office as a general election draws near.”

From the Observer which is serialising the Andrew Rawnsley book – as reported by ConHome.