in the case of a constituency wholly situated in one local government area, the person who under section 41 of the 1983 Act (returning officers: local elections in Scotland) is the returning officer at elections of councillors for the local authority for that area;

in the case of a constituency situated in more than one local government area, such person mentioned above as the Scottish Ministers may by order direct (and an order made under this article may vary, amend or revoke any previous such order).