Organizacja Bojowa as a military arm of the PPS was viewed unfavourably by the other Polish political force, the right-wing "endecja". During the "June Days", as the Łódź uprising in 1905 came to be known in Poland, armed clashes broke out between gunmen loyal to Piłsudski's PPS and those loyal to Roman Dmowski's National Democratic Party ("Endeks"). It was also not unanimously supported by all members of the PPS; in November 1906, a faction of the party split off in protest of Piłsudski's leadership. The Piłsudski's faction was known as "Old Faction" or the "Revolution Faction" (Starzy, Frakcja Rewolucyjna), while their opponents were known as the "Young Faction", "Moderate Faction" or the "Left Wing" (Młodzi, "Frakcja Umiarkowana", Lewica). The Youngs sympathized with the Social Democracy of the Kingdom of Poland and Lithuania and believed that the priority should be cooperation with Russian revolutionaries in toppling the tsardom and creating a socialist utopia first, and negotiation for independence would be easier later. Piłsudski with his supporters from the revolutionary faction of the PPS, continued to plan a revolution against tsarist Russia. However, since then Organizacja Bojowa (temporarily known as Organizacja Bojowa PPS – Frakcja Rewolucyjna) – and Piłsudski – acted increasingly independent from the PPS, whose revolutionary faction would try to organize a more controlled organization called 'Milicja Robotnicza'. Nonetheless the Young faction would soon disappear and Piłsudski's faction would again take the leading role within the PPS.