Former prime minister Tony Blair thought his successor Gordon Brown was "bonkers" and a "malign force" that was "hell-bent" on his destruction, according to his ex-media chief's diaries aired Monday. The extracts from Alastair Campbell's diaries shone a light on the tension and bitterness behind the scenes during Blair's decade in office from 1997, when Brown served as his finance minister. The sections from Campbell's latest volume of diaries, "The Burden of Power: Countdown to Iraq", were published in The Guardian newspaper. Blair and Brown had been the twin driving forces behind the Labour Party's modernisation and return to power after 18 years in opposition, but their relationship soon soured and turned into bitter rivalry. Brown eventually took over from Blair as prime minister in 2007, but lost power in the 2010 general election. In a diary entry from September 2002, Campbell said Blair felt a "dark cloud of GB (Brown) over him the whole time. He said GB was getting desperate and now was acting as a destructive force much of the time." Blair said: "He's brilliant and ambitious but he's also bonkers and I just can't be bothered with it," Campbell wrote. Two months later, Campbell recorded Blair as saying the worst thing about the situation was that "I still try to help him and he basically treats me like ...". "He felt that they were now running a basic destabilisation strategy, though one without a clear outcome," Campbell wrote. "TB (Blair) said if people knew the truth about how GB treats him, they would be appalled. He felt that GB was trying to push him into trying to get rid of him, and he would then seek to mount a challenge." Four days later, Campbell recorded: "The general feeling now, not just in Number 10 but around the Cabinet table too, was that GB was pretty hell-bent on TB's destruction. TB said he still felt we had to try to get it back together but he didn't hold out much hope." But towards the end of November 2002, "TB said he now accepted GB was a largely malign force." On January 6, 2003, Blair said: "I'm going to sack him. I've come to a settled view that he has to go. There was a time when I could make the case that the tension was creative. But it has reached the point where it is destructive and it can't go on," Campbell wrote. The following month, in a meeting about the euro, Blair said the situation was "the worst yet". "He said GB talked to him like he was a five-year-old. If it was serious, he would be worried, but it's a total joke." On May 15, 2003, Blair looked "really fed up". "He said he and GB were in a different league to the rest of the Cabinet as politicians, and GB was the only one who got anywhere near him in terms of ability, which was why he still felt he had to be next."