lack of clarity surrounding actus reus
definition of 'assault', Judges had to determine what it meant
no definition of 'actual bodily harm' - originally, 'any hurt or injury calculated to interfere with the health or comfort of V' R v Miller, redefined definition to include physical and psychiatric injury in R v Chan-Fook
'bodily' - wide interpretation, depart from Parliaments intention (Smith)
Judges should apply law, Parliament create law
breach of separation of powers