During an election there may be situations where there may be conflict regarding the purchase of time, whether a broadcaster makes available the right time at the right moment, or there may be issues between the broadcaster and the party, and he would serve as an arbitrator in that context. Those are his two roles.
Evidence of meeting #82 for Procedure and House Affairs in the 42nd Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was debate.
A recording is available from Parliament.