Mortgagee exclusion clauses are a well-established feature of section 106 planning agreements. It is, however, highly unusual for these provisions to be the subject of judicial scrutiny as they were in the recent High Court case of <strong><em>Westminster City Council v Gem House Residences &amp; Anor [2025] EWHC 1789.</em></strong> The case is eye-catching for this reason alone. But does it have any wider implications?