Proposed law could boost government control over the internet amid a crackdown on those opposed to President Vladimir Putin

Wikipedia shut down its Russian-language page on Tuesday to protest at a bill that would boost government control over the internet amid a crackdown on those opposed to the regime of President Vladimir Putin.

Users who opened the site saw the Wikipedia logo crossed out with a stark black rectangle, and the words "imagine a world without free knowledge" written in block letters underneath.

The bill, due to be considered by parliament on Wednesday, "will lead to the creation of a Russian analogue to China's Great Firewall" the website warned in a statement. The bill calls for the creation of a federal website "no" list and would have to be signed into law by Putin before coming into effect. Internet providers and site owners would be forced to shut down websites put on the list.

The bill's backers, from Putin's United Russia party, argue that the amendments to the country's information legislation would target child pornography and sites that promote drug use and teen suicide. But critics, including Russian-language Wikipedia, warned that it could be used to boost government censorship over the internet.

The Russian justice ministry already maintains a register of more than 1,000 sites that have been deemed "extremist" and ordered to be shut down. The bill appears to realise opposition activists' biggest fear – that a platform that has remained relatively free has become the target of Kremlin ire.

"For the last 12 years, I've lived in happy confidence that the Russian authorities would be smart enough not to censor the internet," Anton Nossik, a leading Russian internet expert, wrote in his blog on Tuesday. "But the situation, unfortunately, is changing."

With Russia's main state television channels under the control of the government, and its few free newspapers unable to be distributed across a vast country with poor infrastructure, the internet has become a growing source of free information. Until now, the Kremlin has limited its attempt to control the internet to paying commenters affiliated with youth group Nashi to leave pro-government comments on critical websites, according to thousands of emails leaked by the Russian arm of Anonymous earlier this year.

Blogs and social networks have been key to organising the mass street protests that have swept Moscow since Putin announced he was returning to the presidency late last year. Alexey Navalny, a leading opposition figure, was relatively unknown until he launched a popular anti-corruption blog.

"The Kremlin swindlers have understood that paid commenters and an army of bots can't help them in any way with their 'ideological struggle for the internet'," Navalny wrote in his blog on Tuesday.

He issued his support for Wikipedia's day-long shutdown, which echoes a similar move by English-language Wikipedia in January to protest the US Congress's consideration of the Stop Online Piracy Act (Sopa).

Congress subsequently put off consideration of the bill amid a global uproar.

Later on Tuesday, the blogging platformLiveJournal joined the protest against the bill. The Russian parliament's consideration of the controversial internet bill comes amid a host of other initiatives that activists say is the biggest attempt since the Soviet era to shut down government critics.

MPs are rushing through votes before entering the summer recess at the end of the week. They are due to consider a bill that would oblige non-governmental organisations that receive foreign funding to brand themselves "foreign agents". They are also likely to consider amendments that would boost fines for defamation. Earlier this year, fines for protesting were drastically increased.