On the point about the Department of Justice perhaps being comfortable with a different course of action, I come back to the discussion about the role of members of Parliament—lawyers and non-lawyers alike, so we can treat them equally. This is one of the ultimate roles of MPs, I would suggest; you can't artificially divide and separate the constitutional imperatives from the social imperatives. In this case, the power of the word that has been established through this whole regime over years has been established.
Similarly, if we refer to the question of how using some other language is somehow an administrative role distinct from the constitutional imperative and the need for the government to communicate this to the public, you can't divide those as well.
The role of the members of Parliament is to see that, all things in balance, the best thing is to retain the terminology.