Bloomberg reports that the Czech parliament has approved a bill banning future government members from owning media. The change in legislation will force billionaire Finance Minister Andrej Babis to surrender control of his influential newspapers if he wants a cabinet post after 2017 elections.

The legislation tightening conflict-of-interest rules, dubbed Lex-Babis by Czech media, also bars companies owned by ministers from tapping state funds. The bill was pushed through parliament in rare cooperation between Prime Minister Bohuslav Sobotka’s Social Democrats and conservative opposition parties. They all trail Babis’s five-year-old ANO, which has eclipsed traditional parties by capturing the protest vote, in opinion polls.

“Oligarchs will have to choose: government membership or subsidies, public contracts and media ownership,” Sobotka said on his Twitter account after the vote on Wednesday.

Babis said he’ll wait for the new law to become effective before consulting lawyers on his options. He decried the bill as an attack by traditional parties, saying they were “desperate and always trying to come up with something” against him.

“It’s unacceptable for me that my basic right to choose what I want to own, or whether I want to go into politics, is decided by someone else,” Babis said.