A top adviser to Russian opposition politician Alexei Navalny said today he is retiring from public activity after calling on the European Union to lift sanctions on one of Russia’s richest men.

The decision by Leonid Volkov, Navalny’s chief of staff and a leading figure in the movement, shocked the opposition, with some seeing it as a gift to President Vladimir Putin.

But it came after prominent journalist Alexei Venediktov, whom Navalny’s team accused of being a Kremlin stooge, leaked in February a letter signed by Volkov and other opposition figures calling on the European Union to lift sanctions on tycoon Michael Friedman and their partners in his Alpha Group business empire.

Volkov said his signature on the document in question had been photoshopped, but revealed he had sent a similar letter to EU foreign policy chief Josep Borrell last October.

“This letter was a big political mistake,” Volkov said, adding that he overstepped his authority and disappointed his colleagues by not informing them of it.

In his October letter, Volkov urged the European Union to expand the number of Russians targeted by sanctions but also to lift sanctions on people who publicly condemn the war in Ukraine and break with Putin.

In particular, he supported the lifting of sanctions imposed on Ukrainian-born Mikhail Friedman, describing him as a liberal who has always kept his distance from Putin.

Friedman has kept a low profile since Russia invaded Ukraine on February 24, 2022, but said early on that the conflict would harm both nations and called for an end to hostilities.

Volkov’s position became untenable when Venediktov leaked that Volkov was secretly lobbying on behalf of one of Russia’s top “oligarchs”.

In a series of tweets, Volkov said he was wrong to believe his approach could “trigger a chain reaction of public condemnation of the war and a split in Russian elites.”

He stated that he therefore decided to “take a break” from his public activity as chairman of Navalny’s Anti-Corruption Foundation. He said he would soon meet with his colleagues and decide whether and how they could continue to work together.

Several opposition figures today expressed their support for Volkov.

“Don’t go into the shadows. Don’t give Benediktov and Putin a reason for such joy,” said Xenia Thorstrom, a city councilor in St. Petersburg.

Many leading opposition figures have fled Russia since Navalny was jailed in 2021 on charges that he and Western governments and human rights groups say were fabricated to silence him.

Now based in Lithuania, Volkov appears frequently on Navalny’s YouTube channel, which has published several investigations into corruption in Russia and condemned the war in Ukraine. Friedman’s current location is unknown.