JERUSALEM — Avigdor Lieberman, Israel’s hard-line defense minister, stepped down from his post on Wednesday after the government agreed to a cease-fire with Hamas to end two days of clashes in Gaza, in a surprise move that could prompt early elections.
The decision by Mr. Lieberman to withdraw his hawkish Yisrael Beiteinu party from Prime Minister Benjamin Netanyahu’s coalition will decrease the number of seats held by the government from 66 to a precarious 61 in the 120-seat Parliament.
Mr. Lieberman also called for early elections, saying the lack of clarity over the country’s security policy must be brought to an end.
“I very much hope that by Sunday, negotiations between the parties will reach an agreed date for elections,” he said.
It takes at least three months to prepare for elections in Israel. The current government’s four-year term is scheduled to run out a year from now.
It was not immediately clear who would replace Mr. Lieberman as defense minister after the resignation comes into effect in 48 hours.
The announcement, made at a news conference in Parliament, came a day after the right-wing government agreed on Tuesday to the cease-fire with Hamas, the militant group that controls Gaza, ending an outburst of intense, cross-border violence.
In Gaza, there were celebrations about what the Palestinians viewed as a rare victory over Israel. Many Israelis, including residents of the south who had been under heavy barrages of rocket fire, censured the government for what they called a humiliating surrender after militant groups fired some 460 rockets and mortars from Gaza into southern Israel.
Explaining the timing of his resignation and appealing to his right-wing constituency, Mr. Lieberman said that he considered the cease-fire to be a “capitulation to terror,” and he listed a number of other recent policy decisions with which he disagreed.
“What we are doing now as a state is buying short-term quiet at the price of serious damage to national long-term security,” Mr. Lieberman said.
The battle to replace Mr. Lieberman may precipitate the beginning of the end of this Netanyahu government. Various parties, including Mr. Netanyahu’s conservative Likud, Mr. Lieberman’s ultranationalist Yisrael Beiteinu, and Education Minister Naftali Bennett’s pro-settlement Jewish Home are all vying for the right-wing vote.
Mr. Bennett, who frequently espouses bellicose positions, is likely to demand the defense job, but Mr. Netanyahu will not be eager to give it to him, according to Israeli political analysts.
A legislator from Mr. Bennett’s party, Shuli Moalem-Refaeli, said that if Mr. Bennett was not appointed defense minister, then Jewish Home would also pull out of the coalition, a move that would bring down the government.
Mr. Lieberman earned a reputation as a blunt-talking, polarizing figure, but his party’s strength has dwindled in recent opinion polls, barely scraping past the electoral threshold. He was named defense minister in May 2016, as part of a political deal augmenting Mr. Netanyahu’s coalition, which had survived for a year with a razor-thin majority of one.
Having served as foreign minister in two previous Netanyahu governments, Mr. Lieberman replaced Moshe Yaalon, a senior member of Likud, who quit over bitter differences with Mr. Netanyahu.