Russia’s leading environmentalist, whose fierce campaigning once threatened the interests of some of the country’s richest men, has moved to Estonia to ensure she is not separated from her children.

Yevgenia Chirikova, 38, is best known for a 2010 campaign opposing the construction of an $8 billion toll highway linking Moscow and St. Petersburg. Chirikova’s investigations shed light on some of the murkier aspects of a project that is partly owned by President Vladimir Putin’s childhood friend. The project, which is under construction, has come under fire because it destroys a federally protected forest even though there were more environmental friendly alternative routes available.

As her allies and environmentalists from other Russian regions face increasing government pressure, Chirikova has opted to leave her homeland.

“It is difficult to work in Russia because they can come for you at any moment like they blackmailed me once with my children,” she told The Associated Press on the phone from the Estonian capital of Tallinn. “Now I’ve eliminated my biggest vulnerability by leaving for Estonia.”

Chirikova said she is in Estonia on a residence permit and that she would not apply for political asylum because this could hamper trips to Russia.

The mother of two, who won the prestigious Goldman Award in 2012, also said she does not want to see her taxes pay for Russia’s “war against the brotherly Ukraine.” Overall, she said the government’s policies are designed to distract attention from a disastrous environmental situation across Russia.

Chirikova’s departure follows the emigration of several prominent government critics in recent years including leading economist Sergei Guriev, who went to France last year. Opposition politician Vladimir Ashurkov also received political asylum in the U.K. in March.

Over recent years, environmental activism in Russia has become a dangerous pursuit. Journalist Mikhail Beketov, who wrote about corruption in Khimki, a town near the $8 billion highway, and campaigned along with Chirikova was left brain-damaged after a brutal beating in 2008 and died five years later.

And Suren Gazaryan and Yevgeny Vitishko, the environmentalists who investigated the impact of the preparations for the 2014 Winter Olympics in Sochi, were slapped with charges for spray-painting a fence.

Gazaryan fled Russia and received political asylum in Estonia in 2013 while Vitishko stayed behind. During the Games, a court ruling converted Vitishko’s suspended sentence into a three-year term in prison. His plea for an early release was rejected last week over a technicality.

Chirikova said she would not want to compare her situation with that of Vitishko but said being a vocal environmentalist in Russia carries inherent risks.

“As soon as a person starts to be efficient at what he does, they begin to threaten you with taking away your children, or slapping you with criminal charges,” Chirikova said.

She added that the only way to campaign in Russia now may be “leaderless resistance so that it’d be unclear who to target.”

Chirikova, who holds degrees in aviation and economics, came second in the Khimki mayoral race in 2012 in a vote largely criticized as rigged.