The 17-year-old was stabbed in the back as she sat with friends in a case of mistaken identity.
The controversy over the duke's ties to Jeffrey Epstein is understood to have been a factor in the move.
The parties took the channel to court after their leaders were left out its head-to-head debate.
US businesswoman Jennifer Arcuri has accused the prime minister of "ignoring and blocking" her.
The National Union of Students say they are "very worried" over similar cladding on student blocks.