Askew was one of the most consistent performers in PDC Floor events enabling him to remain in the World's Top 16 until 2005. However, he struggled to match his early success in TV Tournaments. Askew entered the 2007 World Championship needing to reach the quarter-finals in order to remain in the world's top 32. Askew produced some good form in winning a few matches but just fell short of his target, narrowly losing in the last 16 to Alan Tabern. After dropping out the 32 Askew remained on the cusp of world's top 32 for a while after. His performances on the tour during 2007 earned him a place at the 2008 World Championship where he performed well despite losing out to rising star Adrian Lewis. In 2008, Askew hit a nine-darter on the PDC tour and narrowly missed out on qualification for the World Matchplay. He came within one leg of reaching the 2009 World Championship losing in the final qualifying round 4–5 to Michael Barnard.