Ukrainian President Volodymyr Zelenskyy has stripped four Ukrainian lawmakers of their citizenship for collaborating with the Kremlin, undermining national security, and spreading Russian propaganda.

The four pro-Russia MPs are Andriy Derkach, Taras Kozak, Rinat Kuzmin and Viktor Medvedchuk.

In a video address on Tuesday, Zelenskyy said these “elected representatives chose to serve not the people of Ukraine, but the murderers who came to Ukraine,” adding that “this is not the last decision of that kind.”

Derkach is an independent lawmaker who has been sanctioned by the U.S. Treasury for trying to interfere in U.S. elections. In 2020 he was labeled by the U.S. as “an active Russian agent, maintaining close connections with the Russian Intelligence Services for over a decade.”

The most high-profile of the four MPs is Medvedchuk, a millionaire who used to be the most influential ally of Vladimir Putin in Ukraine. The Russian president is the godfather of Medvedchuk’s daughter.

In 2021, Medvedchuk and his business partner Kozak were put on trial, accused of high treason. 

The State Bureau of Investigations of Ukraine said it had found evidence that Medvedchuk and Kozak were helping Russia to extract oil and gas in occupied territories of Ukraine. In addition, they were accused of handing sensitive data on the location and deployment of Ukraine’s military units to Russian security forces. In June, the State Bureau of Investigations finished its pre-trial investigation and passed the materials to the court. Both deny all the charges.  

Kozak fled Ukraine on February 24, 2021, exactly a year before Russia’s full-scale invasion of Ukraine.

Medvedchuk was put under house arrest and called the criminal charges against him political persecution. He continues to position himself as a serious political rival to Zelenskyy, although in reality his poll numbers do not even put him in the top five.   

After the start of the invasion, Medvedchuk escaped and was on the run for two months before being caught by security forces. In September, he was part of a prisoner swap that saw nearly 200 soldiers who defended Mariupol and its Azovstal steelworks being exchanged for 55 Russian soldiers and the oligarch.

Both Medvedchuk and Kozak, as well as Kuzmin, were influential members of the Opposition Platform for Life party, the largest pro-Russia political force in Ukraine. In June, a Ukrainian court banned the party for repeatedly undermining Ukrainian sovereignty, and ordered its assets be seized.

A month earlier, Zelenskyy had signed a law banning all 11 pro-Russia political parties in Ukraine.

Opposition Platform for Life labeled the ban political persecution and tried to have it overturned in the courts. In September, the Supreme Court upheld the ban. As a result, the remaining MPs split into two new parliamentary factions: Platform for Life and Peace and Restoration of Ukraine.