ed miliband vowed yesterday to end casual employment contracts .
but labour councils and mps hire many workers on zero-hours contracts .
foi requests reveal labour councils have 21,798 zero-hours contracts .
miliband has been accused of hypocrisy after his crackdown backfired .
68 of the party 's mps were revealed to have employed staff on zero-hours contracts over the past two years ; .
22,000 more of the contracts were handed out by labour-run councils , including doncaster where mr miliband is standing for mp ; .
employers and legal experts said his crackdown would cost scores of jobs ; .
statisticians accused labour of using ` unjustified ' propaganda ; .
17 more business leaders came forward to sign a letter supporting the tories in may 's election -- taking the total to 120 .