 He became the second elected "Lehendakari" (President of the Basque Autonomous Community), after José Antonio Aguirre, who had held that office in 1936-60.He was a leading figure in the Basque Nationalist Party (EAJ-PNV) of Navarre in the period 1975-80.In 1979, he was elected president of the Basque General Council, the provisional body preparing the devolution of powers to the Basque Country prior to the approval of the Statute of Autonomy.