ed miliband accused of ` hypocrisy ' after 68 mps used zero-hour contracts .
100 workers and employers from ` all walks of life ' signed letter backing ed .
but signatories included affluent students and union and party activists .
john-jo pierce and rory somerville both pictured in black tie with cigars .
wayne hemingway , red or dead co-founder , has used zero-hour contracts .
a picture caption in an earlier version of this article wrongly stated that rory somerville is 31 years old . we are happy to clarify that mr somerville is 21 and was aged 19 in the photo . the caption also wrongly attributed comments said by deirdre pierce about her son , john-jo , to mr somerville 's mother .