A law coming into force on Wednesday will give the Kremlin greater control over what Russians can access online ahead of a presidential election next March.

Providers of virtual private networks (VPNs) -- which let internet users access sites banned in one country by making it appear that they are browsing from abroad -- will be required to block websites listed by the Russian state communications watchdog.

The law is the latest in a raft of restrictions introduced by President Vladimir Putin's government and is expected to affect journalists and opposition activists, even though several VPN providers say they will not comply.

Videos by the punk band Pussy Riot and the blog of opposition leader Alexei Navalny have in the past been blocked under a law that allows authorities to blacklist websites they consider extremist.

"Journalists and activists who are using this to put out messages anonymously will be affected," Eva Galperin, director of cybersecurity at the US-based Electronic Frontier Foundation, told AFP.

Even if they are able to work around the new restrictions, the law will send a powerful message to activists, she said.

"If you're thinking about taking the steps that you need to stay anonymous from the government, you think maybe it's not worth it."

The law will likely be selectively applied and will probably not affect foreign business people using company VPNs, she said.

The measure is part of a wider crackdown on online communications, which this month saw the popular messaging app, Telegram, fined for failing to register with the Roskomnadzor communications watchdog and provide the FSB with information on user interactions.

Starting from 2018, companies on the Roskomnadzor register must also store all the data of Russian users inside the country, according to anti-terror legislation which was passed last year and decried by the opposition and internet companies.

On Thursday, the Russian parliament's lower house approved a draft law that would let the attorney general blacklist the websites of "undesirable organisations" without a court order.

- 'Less safe, less free' - 

While falling short of a blanket ban on virtual private networks, the new law undermines one of their key purposes and "essentially asks VPN services to help enforce Russia's censorship regime", Harold Li, vice president at ExpressVPN International, told AFP by email.

"VPNs are central to online privacy, anonymity, and freedom of speech, so these restrictions represent an attack on digital rights," Li said. 

"We hope and expect that most major VPN services will not bend to these new restrictions."

Providers ZenMate and Private Internet Access -- which said it removed all of its servers from Russia in 2016 after several of them were seized by authorities without notification -- have already announced that they would not enforce the list of banned websites.

Companies that do not comply are likely to see their own websites placed on the Russian blacklist.

Amnesty International has called the new legislation "a major blow to internet freedom" and Edward Snowden, the NSA whistleblower who lives in Russia, said the measure "makes Russia both less safe and less free".

Laws curbing internet freedoms were drafted following mass protests in 2011 and 2012 against Putin over disputed election results. 

The new measures come into force ahead of presidential elections next March, when Putin is widely expected to extend his grip on power to 2024.

Russia's opposition groups rely heavily on the internet to make up for their lack of access to the mainstream media.

- 'Complete control' -

"The path that Russia chose four years ago is founded on the concept of digital sovereignty," said Sarkis Darbinyan, lawyer and director of the Digital Rights Centre.

"It's the idea that the government should control the domestic part of the internet. Western countries do not support this concept and so what we are seeing today is an Asian-style development of the internet," along the lines of China and Iran, he said.

But Galperin of the Electronic Frontier Foundation noted that even if the Kremlin's end goal is "complete control of communications on the internet", its technical capabilities still lag way behind China with its "Great Firewall".

Many of the invasive measures pushed by the Kremlin are comparable with the snooping powers demanded by Western governments, she said.

"Russia will frequently point to the fact that the FBI and (British Prime Minister) Theresa May want these powers as reasons why they should have them, and why they're compatible with human rights."