I think the rules are fairly clear. Any piece of legislation, regulation, ministerial instruction, or decision by a public servant has to be charter-compliant. The Federal Court Act says that without exception, all of these decisions, by whatever level, are subject to review by the Federal Court. So are the instructions themselves subject to judicial review? Yes, they are. Is their application by officers of the department subject to judicial review? Yes, it is.
On May 13th, 2008. See this statement in context.