Russia's Prime Miniter Dmitry Medvedev speaks at a congress of the ruling party United Russia
Russia's ruling party on Saturday approved Prime Minister Dmitry Medvedev as its new chief in a bid to reverse flagging popularity that stoked opposition protests against the Kremlin.
A United Russia congress in Moscow overwhelmingly confirmed by a show of hands Medvedev's candidacy to take over from President Vladimir Putin as party leader, with no apparent opposition and no other candidate contesting the post.
Medvedev's move to become a card-carrying party leader is a key plank in Russia's new power structure that saw him cede the Kremlin to Putin earlier this month after serving four years as president.
In a highly-orchestrated event, Putin formally announced Medvedev's candidacy at the central Manezh hall next to the Kremlin to a crowd of 3,000 guests and delegates.
"I consider United Russia my key ally and partner," said Putin, dispelling speculation that the party has been sidelined by the Kremlin and could even be disbanded after it lost support in December parliamentary elections.
Putin has been the leader of the party since 2007, although curiously never joined. He decided to fully step aside in April after announcing that leading the party is inappropriate for the president.
Medvedev -- who previously criticised United Russia and compared it to political stagnation of the Soviet Union's Brezhnev era -- this week formally joined the party and vowed to reform it from the inside.
He said during the congress that the party should undergo "revolutionary" changes in order be "more understandable to people" rather than seem "imposed from above" and vowed to cleanse it of unworthy members.
"United Russia has been in power for a considerable amount of time," Medvedev said. "There is a factor of tiredness beginning to play out against it."
United Russia would not have success if it was just seen as a "voting machine", Medvedev said.
But after suggesting more democracy in party ranks and using social networks in its work, he made clear that the party's target was to win the next parliamentary elections in late 2016.
"In five years, when there are new elections into the State Duma, United Russia must win," he said to roaring applause as a Russian flag waved slowly behind him on a giant screen.
Dominating the Russian parliament since 2003, the party supported Putin in his second election into the presidency in 2004 and has essentially been a rubber-stamping tool of the Kremlin.
But its lavish congresses, unattainable campaign promises and adulation of Russia's executive leaders earned it comparisons with the Soviet-era Communist party that monopolised political life in the country for decades.
Last year the opposition waged a campaign ahead of the parliamentary polls asking voters to cast their ballots for any party but United Russia, dubbing it the "party of crooks and thieves" and inundating Internet blogs with videos and posters discrediting the faction.
A growing popular perception of United Russia as arrogant and corrupt fuelled the protests against Putin that broke out in December over claims the parliamentary polls were marred by ballot-rigging.
Faced with loss of popularity of the majority party, Putin created a new coalition, the All-Russia People's Front, which he relied on in his presidential campaign.
United Russia received only 49.3 percent of the popular vote in the December 4 elections, hanging on to more than half of the parliament seats only by a quirk of Russia's electoral law.
The party is also likely to face more resistance in regional and city elections as the notoriously disjointed opposition learns to better mobilise over the Internet, even holding primaries to select unified candidates.