My understanding—and I think Beisan could also answer this—is that if an employee is reporting directly to their MP, they might feel intimidated doing that, especially if they're on probation. The MP could also be the harasser, so it might not be ideal for them to report to the MP. Also, there are political reasons that an employee might not want to report to the MP. For example, if the harassment is coming from their own party or another party, reasons of party loyalty and hyperpartisanship could make the employee feel too intimidated to report. Again, I believe there should be a completely independent third party to report to.
On March 26th, 2018. See this statement in context.