"Further to your telephone call to this office on12 August 1996 the Chairman directs me to write to you as follows.
" ... an interlocutory order of an industrial tribunal or of a chairman sitting alone we would define three issues (a) Is the order made one within the powers given to the Tribunal? (b) Has the discretion been exercised within guiding legal principles? eg as to confidential documents in discovery issues. (c) Can the exercise of the discretion be attacked on Wednesbury principles?"