The Legislation Ministerial Committee voted on Monday to advance the so-called anti-Barkat bill, which would limit any elected official and his family to donations of NIS 100,000 a year for political activity, including polls, staff and rallies when no elections are taking place.
The ministers decided to bring it to a vote in the Knesset plenum in a preliminary meeting and then change it to a special committee led by Justice Minister Gideon Sa'ar.
The Likud faction will now have to figure out how to handle the political hot potato ahead of the vote in the plenum.
Blue and White ministers voted against the bill in the committee.
A Panels Research poll taken for The Jerusalem Post Group last week found that Barkat could bring the Likud many more seats than other potential successors to Prime Minister Benjamin Netanyahu, including MKs Yuli Edelstein, Israel Katz and Miri Regev. Barkat, who is the Knesset's only billionaire, is expected to run for Likud leader if Netanyahu decides not to run.