The Transylvanian Memorandum
At the 1887 national conference of the PNR the participants voiced their grievances in regard to the worsening situation of the ethnic Romanians in the Kingdom of Hungary and decided to present the Emperor a petition encompassing the growing complaints against the consequences of the Ausgleich: the discrimination and the Magyarization process conducted against the ethnic Romanians, their underrepresentation in the Hungarian Parliament through the electoral laws despite their demographic majority in Transylvania and the way the Ausgleich was adopted, without consulting the Transylvanians. Nevertheless, at the next national conference (1890) it was decided to postpone this endeavor to a later, more convenient date. As a result of this decision, in November 1891, Pop de Băsești asked for the resignation of the PNR president Vincențiu Babeș and argued that the leadership of PNR should be taken over "by an appeasing person, with a calm temperament and above all totally independent and master of his own ideas and beliefs".
Heeding his call, the delegates of the PNR elected in 1892 Ioan Rațiu as president and Pop de Băsești as vice president of the PNR. The new leaders decided to task Vasile Lucaciu and Iuliu Coroianu with drafting and publishing the petition. Under the name of "Transylvanian Memorandum", the petition was approved by the PNR on 25 March 1892 and brought on 28 May 1892 to Vienna by 300 delegates of the PNR (among them 48 members from Szilágy County, including Pop de Băsești) to be presented to the Emperor Franz Joseph in a sealed envelope. At the request of the Hungarian government, Franz Joseph did not receive the delegation and forwarded the unopened envelope to the Hungarian Prime-Minister, which in turn forwarded it unopened to the Torda-Aranyos Ispán in order to be returned to the sender, Ioan Rațiu, arguing that the Hungarian Ministry of Interior was not authorized to present the Emperor with petitions of individuals not entitled to represent the ethnic Romanians in Hungary.
Met with refusal, PNR published the memorandum in the press. Tensions ran high: Rațiu's home in Torda was damaged by Hungarian demonstrators, leading to protests in Romania. After a while, the government in Budapest gave in to pressure from the Hungarian nationalists and in May 1893 it launched proceedings against the PNR president, Raţiu, the vice president, Pop de Băsești, the secretaries Vasile Lucaciu and Septimiu Albini, and other PNR leaders who acknowledged their involvement in drafting and publishing the petition.
Consequently, on 7 May 1894, 14 leaders of the PNR, including Pop de Băsești, were put on trial in Kolozsvár for various charges, ranging from disturbing the peace to high treason. On 25 May 1894, the verdicts were handed down: all the accused were found guilty, and on 27 May 1894, the judge sentenced them to imprisonment for terms ranging from 5 years (Vasile Lucaciu) to 1 year, in total 31 years and 2 months. Pop de Băsești was handed the mildest sentence (of one-year imprisonment), his only regret being that he received less than the others. Present at the trial, Octavian Goga witnessed that moment: "All the accused acknowledged the sentences in a manful manner. Leading the group, Father Lucaciu seemed to be an ancient hero. Mr. Rațiu came in with his head held high. [..] Only Brother Gheorghe wept because he said they mocked him by handing him a milder sentence than his fellows."
On 28 July 1894, the PNR was banned by the Hungarian authorities, who invoked the lack of a party statute and "relations with foreign elements".
Pop de Băsești served his sentence in the Vác prison until 5 August 1895. As his wife Maria passed away he was shortly released on parole on 11 June 1895 so that he could attend her burial. Eventually all signatories of the memorandum were pardoned by Emperor Franz Joseph in 1895, following secret negotiations between Austria-Hungary and the Romanian king Carol I.