Anton du Beke has confessed how envious he can get over watching pairs compete on the dance floor while he's a judge, ahead of the new Strictly Come Dancing series launch this week.The 20th series of the BBC show will see 15 celebrity contestants – including TV presenter Helen Skelton, EastEnders actor James Bye, singer Fleur East and former England footballer Tony Adams – taking to the dance floor. Du Beke will once again join Shirley Ballas, Craig Revel Horwood and Motsi Mabuse on the judging panel when the hit dance competition returns to screens on BBC One and BBC iPlayer on 23 September.