It is both to me. Why do you make that distinction anyway? It is a legal as well as moral matter. Would say that there isn't much to argue about the legal issue of discriminating religious marriage verses civil union, it is the case and not much more over the fact that there can't be any legitimacy today as an EU member state in subordinating the access to married couple rights to an appearance at a phony city hall show for a religiously married couple.
Now the moral side of it lays into the need to be coherent when you face a fierce opposition on a legislation. To be heard on the before the law equality for all couples asking the assistance of the state to celebrate their union, while facing a clear divide and a number of controversies about the project, there can't be two standards, one for religious couple seeking the assistance of a Church to act their union that do not open the door to the married couple rights and one for those seeking the assistance of the state. To be heard on the Equality before the Law it needs to be true regardless of the couple's beliefs and choice of who's the couple seeks assistance to celebrate their union.