In a fic I'm working on -- bearing in mind this isn't any country on planet Earth, but it's canonically established that the current government in place is a parliament. In the scene I'm on, a member of the military, a corporal, actually, has been called into a special meeting before the house of parliament. The meeting was basically a review of some events which occured and an offer they wanted to make to him. It's a rather formal, official meeting, and the character being put on the hot seat would conduct himself accordingly, to be sure.
That said, I've been googling, but all I've found were how members of a parliament speak to other members, and how to address a letter to a member of parliament. What I have here is a non-member addressing one particular one verbally.
If it were me, in America, I'd likely be saying "Congressman" (if in the House of Representatives) or "Senator" (if in the Senate) but I'm not sure what would be correct here in this instance. Since this isn't England, or any country on Earth, there's liable to be some leeway, but I need to know where the boundaries are to know how much leeway, if any.