A Court, including a judicial review is not a forum for “debate”. The purpose of a COURT OF LAW. Is to determine what the law is, where there is a dispute, about the meaning of a specific piece of legislation and/or the application of it.
A judicial review, is in a High Court specifically for complaining about Public bodies, who may have misapplied duties under a piece of legislation, ignored them all or in part, or fettered a discretion, provided for.
A person or a legal person, as in an organisation, may apply to intervene as long as they have sufficient standing, a legal point to make contrary to the applicants claim, or to agree and add a specific issue of a legal concern to them.
A person or persons, cannot apply to be an intervenor with no legal point to make.
HTH