He was sworn in as premier later that day .
Portraying himself as a strong leader who was closer to the Bjelke - Petersen mould , Cooper launched a leadership challenge and toppled Ahern as party leader on 25 September .
Cooper was sworn in as premier later that day .
Portraying himself as a strong leader who was closer to the Bjelke - Petersen mould , Cooper launched a leadership challenge and toppled Ahern as party leader on 25 September .