The party was outlawed in July 1947. That month, Ion Mihalache attempted to flee the country in an airplane, which landed at Tămădău, allegedly to establish a government-in-exile ("see Tămădău Affair"). That was judged as an act of treason, and both Maniu and Mihalache faced a kangaroo court that sentenced them to life imprisonment at hard labour; given their advanced age, that amounted to a death sentence. The show trial, signaling the suppression of opposition groups, was a significant step towards the establishment of an undisguised Communist regime in Romania.