According to the guidelines provided in the text on fair and unfair political campaigning, ...

According to the guidelines provided in the text on fair and unfair political campaigning, candidates
  can be hard hitting and also behave in an ethical manner, which can consist of:
 
  a) Criticism of a policy decision, rumors and/or innuendo, and personal attacks
  b) Unsubstantiated charges of misconduct, questions about leadership ability, and distortions and /or
  lies
  c) Personal attacks, criticism of a voting record, and comparison of experience
  d) Questions about leadership ability, debate of tough political issues, comparison of experience.