The media-freedom group Reporters Without Borders (RSF) says the Russian government’s “draconian and defamatory” decision to list the Meduza website as a “foreign agent” may force one of the country’s most popular independent news sites to shut down.

The listing is “a massive blow to media pluralism in Russia,” the Paris-based RSF said in a May 5 statement.

“We call on the Russian Justice Ministry to abolish this draconian and defamatory register of ‘foreign agent’ media, which exists solely to enable the government to tighten its grip on the press,” said Jeanne Cavelier, RSF’s director for Eastern Europe and Central Asia.

Meduza, which is based in Latvia, is one of Russia’s most popular and influential media outlets, claiming some 13 million unique visitors each month.

The Russian government included Meduza in the “foreign agent” register on April 23. Meduza is appealing the designation and has launched a crowd-funding campaign to compensate for lost advertising revenues that forced it to curtail operations.

Just in the last week, Meduza closed its offices in Riga and Moscow, slashed staff salaries, and halted the use of freelancers.

The European Union on April 24 said “it is extremely concerning that Russian authorities continue to restrict the work of independent media platforms, as well as individual journalists and other media actors.”

Russia’s so-called “foreign agent” legislation was adopted in 2012 and has been modified repeatedly.

It requires nongovernmental organizations that receive foreign assistance and that the government deems to be engaged in political activity to be registered, to identify themselves as “foreign agents,” and to submit to audits.

Later modifications of the law targeted foreign-funded media, including RFE/RL’s Russian Service, six other RFE/RL Russian-language news services, and Current Time, a network run by RFE/RL in cooperation with VOA.

Earlier this year, Russian courts began imposing large fines against RFE/RL for failing to mark its articles with a government-prescribed label. RFE/RL is appealing the fines.

RFE/RL has called the fines “a state-sponsored campaign of coercion and intimidation,” while the U.S. State Department has described them as “intolerable.”

Human Rights Watch has described the “foreign agent” legislation as “restrictive” and intended “to demonize independent groups.”