R (Wilson) v Prime Minister [2019] EWCA Civ 304 is a UK constitutional law case, involving judicial review of the Brexit Referendum in 2016. The claimants, including Wilson, argued that illegality through Russian interference, criminal overspending by Vote Leave and criminal investigation into the largest donor, Arron Banks, before and during the referendum undermined the integrity of the result, and rendered the decision to leave void. The application was refused in the High Court. In December 2018, the claimants lodged an appeal to the Court of Appeal. This was rejected on 21 February.