Dmitry Medvedev speaks at the Russian State Duma's extraordinary plenary session
Russia's new President Vladimir Putin on Tuesday won parliamentary approval for his predecessor Dmitry Medvedev to become prime minister, as protesters tried new tactics to keep up pressure on the Kremlin.
Russia's lower house of parliament overwhelmingly confirmed former head of state Medvedev as prime minister after he was nominated by Putin in accordance with a job swap agreement first announced in September.
Medvedev was backed by 299 deputies in the State Duma with 144 voting against his nomination, sealing Russia's new power structure after Putin served as premier and Medvedev as president for the last four years.
In a dry speech in which he cited Marxist philosopher Friedrich Engels, Medvedev vowed: "We will have to consolidate society around the solution of key tasks, and prove that the state is inseparable from the people."
Putin aggressively defended the private decision to trade places, which added to the anger many Russians felt about fraud-tainted legislative polls in December followed by Putin's controversial March presidential election victory.
"This decision (on the job swap) was taken by me long ago, I have said this openly.
"We have changed nothing and presented nothing in front of society or parliament that could be called a trick or a political game," said Putin.
Medvedev's confirmation at the hearing had been essentially assured after both the ruling United Russia party that he now heads and a largely pro-government bloc of the ultra-nationalist lawmaker Vladimir Zhirinovsky committed their full support.
But in a sign he may not get the smoothest of rides from this parliament, the opposition Communist Party and A Just Russia largely voted against and Medvedev fell short of winning the 300 votes reportedly sought by the Kremlin.
As Putin and Medvedev sealed their job swap, police played a game of cat and mouse with protesters who had spent the night outdoors in central Moscow following Putin's opulent inaugural ceremony that saw him sworn in for a third term as president Monday.
Police arrested about 50 anti-Putin protesters Tuesday evening, after earlier chasing them from the spot near the Kremlin where they spent the night, an AFP correspondent said.
Officers then chased the activists to yet another spot and made more arrests, Interfax news agency reported.
Those arrested included one of the leaders of the protest, anti-corruption blogger Alexei Navalny, as well as television star Ksenia Sobtchak and lawmaker Ilia Ponomarev from the centre-left A Just Russia party, Interfax said.
Navalny had already been briefly detained earlier in the day with fellow protest leader Sergei Udaltsov, a leftist activist.
Police have said they have made almost 750 arrests since Sunday in Moscow as opposition protesters defied a heavy riot police lockdown in the city.
Several hundred people had joined the sit-in overnight, making a point of not brandishing a single political slogan.
"We spent the night out here because it is the only way to show that we too have something to say," said student Nikita Safanov, 20.
Spending the night in the open appears to be a new tactic by the opposition, whose more radical wing has called for civil disobedience to ensure their voice is heard. Navalny had described the action as an "indefinite popular walkabout".
"I awfully want to sleep," Navalny said in a Twitter post. "Two nights without sleep. Last night I slept at Kitai Gorod, and the day before at Yakimanka," he said, referring to police stations in central Moscow.
After Sunday's mass anti-Putin protest ended in violence and bickering between the opposition, Navalny and Udaltsov appeared to be preparing to hold repeated small-scale pickets to provoke the police.
"We have to do it until they realise: this is our city, we go for a walk wherever we want and whenever we want," opposition activist and writer Boris Akunin said in a blog post.