Fr Ray in England is priest at an old Catholic Church in Brighton and considers whether to use the high altar and celebrate mass ad orientem. He decides not to because his diocesan authorities would never allow it.

Now this confuses me. I am no liturgical scholar, nor I am a canon lawyer, but are there actually instructions anywhere that mandate the versus poplulum position for saying Mass? I’m really asking those of you who know more than I do about this. After all, I am a new priest and a convert at that, and I admit to having some gaps in my formation and reading. My question is, “Do the rules allow us to say Mass facing the people or say we must?”
If they merely allow and do not say we must, then why do the rubrics of the Novus Ordo assume that we are facing ad orientem? In two crucial places the rubrics say that the ‘priest should face the people’. One is at the prayer, ore fratres–brothers pray that my sacrifice and yours… and the other is at the ecce agnus dei–behold the Lamb of God. If he is instructed at these two points to face the people, then the assumption is that he has not been facing the people.
I know of one priest who started to celebrate Mass ad orientem and was called on it by his diocesan authorities, but when he explained his position and asked for clarification on where it was mandated that he celebrate facing the people (and not just allowed) he wasn’t given a satisfactory answer. His point was that the universal church allows celebration ad orientem and not even a diocesan bishop can prohibit what the universal church allows or mandate what the universal church prohibits.
I suppose it is a question for Fr Z.