MOSCOW — President Vladimir Putin accepted the leadership of the dominant United Russia party Tuesday, securing his grip on power after he leaves the Kremlin and becomes prime minister next month.
He was quickly approved as leader in a unanimous vote during a party congress that mixed promises of a bright Russian future with traditions from the Soviet past.
Putin's decision to lead United Russia, announced just three weeks before he cedes the presidency to his hand-picked successor, Dmitry Medvedev, left little doubt that he intends to remain at the forefront for years to come.
He was elected chairman for a four-year term, giving him a strong power base during Medvedev's presidency and a potential springboard for a return to the Kremlin in 2012.
Putin cast the move as a step toward European-style democracy for Russia and said it would ensure that Russia's political bosses and bureaucrats functioned as a "single organism" for the good of the people.
"Today even more than before, we need the consolidation of political forces and the spiritual unity of our people," he said after all 577 delegates raised their blue, red and white cards in unison to approve his nomination.
But Putin's decision could undercut the authority of Medvedev. Like the unanimous vote, it evoked memories of the Soviet era, when the Communist Party chief held the real power and the formal head of state was little more than a figurehead.
Speaking before Putin, Medvedev said he supported Putin taking the party leadership, calling it a "logical and timely" step.
Both he and Putin said it would improve coordination between government and parliament.
Putin has promised not to shift any presidential powers to the prime minister. But he has made no secret of his plans to use the Duma to ensure that his will is carried out even after he steps down as president.
He put his name at the top of the United Russia ticket in December parliamentary elections, helping it win 70 percent of the seats in the State Duma, the lower house, and cast the sweeping victory as a vote of confidence in himself and his policies.
But Putin has never become a member of United Russia, instead cultivating the image of a czar-like figure who is above party politics — which many Russians see as a corrupt, crass business.
United Russia's two-thirds majority in the Duma is sufficient to support impeachment of the president and initiate constitutional changes.
Putin and Medvedev both stress they will rule in tandem, and no major rift is visible.
But a darker scenario may figure into Putin's calculations: In the event of a future power struggle, formal leadership of the party — with its clout in parliament and across the country — would enhance his arsenal.