The University of Sussex has launched a High Court challenge to overturn a record £585,000 fine imposed by England’s higher‑education regulator, the Office for Students (OfS). Sussex argues the regulator exceeded its legal powers when it found the university’s trans and non‑binary equality policy chilled free speech, and says procedural bias tainted a three‑and‑a‑half year probe. Lawyers for Sussex, led by Chris Buttler KC, told judges the OfS treated a two‑page equality note as a governing document it had no authority to police and that a friendship between an OfS official and a former Sussex academic created a conflict. If the High Court sides with Sussex it could curb the OfS’s authority to enforce speech rules across English universities and reset how regulators assess internal policies. The hearing will test how far the OfS may go in policing campus governance and will be watched by university leaders balancing equality rules, staff safety, and academic freedom.