He won a seat in the Austrian House of Deputies in 1897, and, during his mandate, co-founded the Romanian National People's Party, which he also represented in the Diet of Bukovina.
Popovici and Iancu Flondor led the party's autonomist wing, which rejected compromise with the Austrian administration and demanded national rights for the Romanian Bukovinians.
Born in Czernowitz (Cernăuți), in Austrian-ruled Duchy of Bukovina, his parents were the Romanian Orthodox priest Eusebiu Popovici (1838–1922) and his wife Elena Hacman.
[4] Eusebie had embraced Romanian nationalism from the 1870s, against the conservatism of the boyar class; George radicalize himself even further, by introducing social demands into the nationalist program and seeking direct backing from the peasants.
[8] In 1897, he returned to Czernowitz, after a study trip to Vienna, in order to campaign for a seat in the Austrian House of Deputies at the March election, joining the Concordia Society (or National Romanian Party, PNR) of Ioan Zotta and Modest Grigorcea.
[9][10] He won the seat with 597 of 625 votes cast, and represented the southern portion of Bukovina: Storojineț, Siret, Rădăuți, Suceava, Gura Humorului and Câmpulung Moldovenesc.
[12] Dissatisfied with the conservative Concordia, in April 1897 Popovici entered the Romanian National People's Party (PNPR), a more radical nationalist group whose ideologue was Iancu Flondor.
[15] In autumn 1897, Popovici proposed before parliament the establishment of an appeals court for Bukovina, and participated in a peasants' assembly at Vienna that gathered together representatives of the empire's rural Romanian population.
[20] In the spring of 1899, he signed his name to a formal protest against the Bourguignon von Baumberg, the Bukovina Governor, accusing him of being anti-Romanian and of censoring the local nationalist press.
[23] By 1900, Popovici had stopped participating in sessions of the Diet, in protest at the older Bukovina Romanian politicians' policy of concessions and patience with the Austrian authorities.
[24] The PPNR split into factions, but the core group, steered by Flondor and Popovici, endured, hoping to rely on renewed support from the Romanian peasantry.
He refused to run again for a vacated seat the House, citing "personal reasons"; his absence cleared the way for Tudor Flondor, who was Iancu's brother and political rival.
[19] He was working on a large-scale volume dealing with the history of Romanian law, but never finished it; instead, he helped his fellow nationalist historian, Nicolae Iorga, reviewing for print his texts in German.