With two of Mr Corbyn's opponents - Andy Burnham and Yvette Cooper - having served in the Cabinet under Gordon Brown and also having been close allies of Ed Miliband and the third, Liz Kendall, tagged as the "Blairite" candidate, Mr Corbyn was able to associate his rivals with the erosion of Labour support during the past decade and argue effectively that only he offered a true break from the recent past.