Ukrainian lawmakers on Thursday approved a law aimed at limiting the influence of oligarchs on politics. The move comes a day after the car of a top aide to Ukrainian President Volodymyr Zelensky came under gunfire, an incident the president said could have been triggered by the reform.

The law, initiated by Zelensky, contains a definition of an oligarch and bars those who fall under it from funding political parties or taking part in the privatization of state assets. It passed its first reading in July, and on Thursday 279 out of 450 lawmakers voted to adopt it. It will come into force after the president signs it.

The law defines oligarchs as individuals who own significant financial assets and media outlets, and requires oligarchs to register as such. It may affect Ukraine’s former president and candy tycoon Petro Poroshenko and businessman Ihor Kolomoisky, who backed Zelensky at the 2019 election and controls Ukraine’s most popular TV channel, 1+1.

The law also requires state officials to declare their dealings with oligarchs.

“The law should be the first step in changing the oligarchic system in Ukraine, which has become the reason for the rampant corruption that is poisoning all spheres of life,” Volodymyr Fesenko, a Kyiv-based political analyst and head of the Penta Center think tank, told The Associated Press.

“Zelensky is trying to distance himself from all of the oligarchs and change the vicious system in which six or seven people controlled the politics and the business in all of Ukraine,” Fesenko said.

His opponents say they fear the legislation could be applied selectively to concentrate power in the hands of the president.