After the 2005 election defeat Don Brash's leadership of National came under scrutiny from the media, and political watchers speculated on the prospect of a leadership-challenge before the next general election due in 2008. Don Brash resigned on 23 November 2006, immediately before the release of Nicky Hager's book "The Hollow Men", which contained damaging revelations obtained from private emails. John Key became the leader of the National caucus on 27 November 2006. Key fostered a more "centrist" image, discussing issues such as child poverty.