Diepeveen graduated with a degree in law from the Erasmus University Rotterdam and worked as a fraud investigator and later as a company director before entering politics.[2][3] He served in the Provincial Council of Gelderland from 2019 to 2024, where he was group leader of the party.[4] Diepeveen ran for the European Parliamentin June 2024 as the PVV's sixth candidate. The party secured six seats, but Diepeveen was not directly elected as lijstduwerGeert Wilders met the preference vote threshold. Wilders declined his seat, and Diepeveen was sworn into the European Parliament on 16 July 2024.[5][6]
^Diepeveen was not elected despite his party's result due to Geert Wilders meeting the threshold for preference votes. However, he did become a member of the body as Wilders declined his seat.