Running against an obscure rival, the son of Indonesian President Joko "Jokowi" Widodo is expected to cruise to victory in an election next month for the post his father once held as mayor of Surakarta.

The political aspirations of his eldest son, Gibran Rakabuming Raka, have raised suspicions that the president, widely referred to as Jokowi, is forming a new dynasty to elbow its way in among Indonesia's old elites.

Unrelated to the powerful families that have dominated government, business and the military in Southeast Asia's largest nation, Jokowi was regarded as an outsider when he was elected in 2014.