Yisrael Beytenu leader Avigdor Liberman said Thursday that he will back legislation to ban any members of the Knesset who are criminally indicted from serving as prime minister.
Liberman's announcement means that a draft bill backed Wednesday by Blue & White chairman Benny Gantz may receive a majority in the 120-strong Knesset.
Interim Prime Minister Benjamin Netanyahu's Likud won 36 seats in Monday's election, the largest of any party, but his union of right-wing, religious factions was three lawmakers short of the 61 seats needed to form a viable coalition government.
Gantz's Blue & White party won just 33 seats, and his center-left bloc can muster a maximum of 55 seats.
Liberman once again found himself in the role of potential kingmaker as his party's unaligned seven seats could push either Netanyahu or Gantz into pole position and tapped by President Reuven Rivlin to form a government.
Yisrael Beytenu said Thursday in a statement: "At the recently ended faction meeting, [the party] decided to promote two laws. The first law proposes a term limit for the prime minister. The second law prevents an indicted MK from forming a government."
The draft legislation is being put together by Blue & White along with Labor-Gesher-Meretz and the Joint List. It can only be presented in the Knesset once the new parliament has been sworn in, some two weeks from now.
In order to guarantee the bill's passage, Gantz will have to muster the largest number of MKs to back him as the next prime minister, receive the mandate to form a government from the president, and then take control of the Knesset's Arrangements Committee.
He would also have to see the election of a new Knesset speaker to replace Likud's Yuli Edelstein in order to ensure that the bill makes it through within certain deadlines.
Right-wing politicians have denounced the law, claiming that it is legislation specifically designed to prevent Netanyahu from forming a government.
On Wednesday, sources claimed that Blue & White intended to make the law applicable only from the next parliament so that it would not be perceived as a personal move against Netanyahu.
Even so, it would prevent Netanyahu from trying to push for a fourth election since April 2019 rather than compromise with parties outside his right-wing bloc of 58 MKs.
Liberman, however, wants the law to take effect immediately, meaning that if it passes, Netanyahu would not be permitted to form a government.
Political pundits say that Liberman's announcement is a dramatic move, which for the first time, shows him clearly taking sides in the battle between the center-left and right.
"Netanyahu lost the majority in the Knesset a year ago but still ruled," said a senior political source.
"Liberman's announcement changes the equation and will, for the first time, allow far-reaching parliamentary moves that had previously been unimplementable."
The Yisrael Beytenu leader, whose handful of seats could tip one bloc or the other into a majority, announced before Monday's election – the third in less than a year - that there would be no fourth round of voting and that this time he would take sides.
At the same time, he made it clear - even after the polls closed - that he would not join a government with Netanyahu.
Despite this, Yisrael Beytenu insists that the party's position on the bill against Netanyahu does not mean that Liberman will automatically recommend Gantz as the person to form the government.
Instead, the party said, Liberman will announce his decision after consultations.
Netanyahu on Wednesday slammed the draft law, saying that, "the move led by Gantz undermines democracy."