The State Duma committee that drafted the bill said it is necessary to combat Web sites that carry child pornography, drug promotion material and advice on suicide, and said the law would bring about the creation of a federal agency to rule on which Web sites should be closed down, RIA Novosti reported Wednesday.
Critics were quick to slam the justification.
"It is always argued that these laws are against extremism, child pornography, and so on, but this legislation will hit the opposition and freedom of political expression," Alexander Morozov, a popular blogger and head of the Center for Media Studies think-tank in Moscow, said.
The Russian-language Wikipedia Web site closed down for a day Tuesday and blacked out its logo in protest of the bill.
Opposition leader Alexei Navalny, a popular anti-corruption blogger, wrote on his blog this week the bill would transform the Internet into a "Zombie Box" -- opposition slang for national TV.
Government control of national television stations has left the Internet to play a major role in the rise of unprecedented dissent against the 12-year rule of President Vladimir Putin.
The bill will go to the Parliament's upper house and could become law Jan. 1.