I have been approved as a prospective candidate of the 〇〇 political party for the upcoming city council elections in May.
ーI have been approved as a prospective candidate of the 〇〇 political party for the upcoming city council elections in May.
「今度の5月に行われる市会議員選挙で、〇〇政党の公認候補予定者となりました」
I have been approved as a prospective candidate of the 〇〇 political party で「〇〇政党の公認候補予定者となりました」と言えます。
prospective candidate で「候補予定者」
〇〇 political party で「〇〇政党」
city council elections で「市会議員選挙」
ご参考まで!