Prominent opposition lawmaker Ilya Ponomaryov said Wednesday that he was quitting his political party, A Just Russia, but hoped to remain in the State Duma as an independent deputy.
No reasons for the resignation were specified, but Ponomaryov's relations with his party leaders have been tense for months over his activity in opposition street protests and affiliation with an outside political movement, the Left Front.
Ponomaryov told a news conference that he had notified the party's chairman, Sergei Mironov, of his resignation.
"I told him I do not consider myself an enemy of A Just Russia," he said, RIA Novosti reported.
The resignation comes after Mironov was chosen to resume his position as chairman earlier this week, a move observers said would bring A Just Russia closer to the Kremlin.
Ponomaryov said he hoped to form a multipartisan coalition in the Duma that would work closely with billionaire Mikhail Prokhorov's Civil Platform party.
Another member of A Just Russia, Dmitry Gudkov, was expelled from the party this spring but has remained a Duma deputy, Ponomaryov said.
Nikolai Levichev, the leader of A Just Russia's faction in the Duma, said Ponomaryov should not expect to remain in the legislature.
"If a person receives his mandate through a party list, then, upon leaving the party, he should surrender his mandate, without waiting until he joins another party," Levichev said.
Gudkov and Ponomaryov were both given an ultimatum earlier this year, to choose to either renounce their external associations or leave the party. Ponomaryov opted to distance himself from the Left Front, while Gudkov was expelled.
Ponomaryov "has chosen his way" by resigning, and "whose way turns out to be correct, time and results will show," Mironov said, RIA Novosti reported.
The 38-year old politician started his career as a youth leader in the Communist party, but left in 2006, a year before being elected to the Duma as a member of A Just Russia from the Novosibirsk region.