In Tweed v Parades Commission for Northern Ireland [2006] UKHL 53, the House of Lords considered the difference between the approach to disclosure in judicial review proceedings when the proportionality of a public authority's decision is and is not in issue. It held that where the proportionality of a public body's restriction on a fundamental human right was in issue, there was no justification for the existing "blanket" rule that there had to be a question mark over some aspect of the public authority's written evidence before the court would permit the documents which "sat behind" that evidence to be disclosed. Having said that, the court recognised that ordering disclosure in judicial review proceedings where proportionality was in issue would remain "exceptional." In this case, because the information in the documents was subject to an obligation of confidence, an incremental approach was to be adopted with the trial judge inspecting the documents in the first instance to see if they did in fact support the applicant's case.

This case is a useful exposition of the difference between the court's approach to disclosure in ordinary civil proceedings and in judicial review proceedings.