JERUSALEM — Prime Minister Benjamin Netanyahu's self-declared victory in Israel's election last week seemed farther away than ever Monday as his rival, Benny Gantz, took new steps aimed at keeping him from attaining a governing majority in parliament.

In an effort to break the country’s year-long political deadlock, Gantz reached out publicly to some unlikely coalition partners, betting that their shared goal of ousting Netanyahu could bring them together.

Gantz, a former military chief, still faces an uphill struggle to form a new government and become prime minister. His center-left Blue and White party won three fewer seats than Netanyahu’s right-wing Likud in last week’s vote. And success would require Gantz winning — and accepting — support from the Joint List, a slate of four Arab-majority parties representing Israel’s roughly 1.8 million Arab citizens.

If he does manage to secure their backing, his allies in Israel’s 120-seat parliament, or Knesset, would outnumber those of Netanyahu’s bloc of right-wing and religious parties, affording Gantz the chance to scrape together a narrow coalition government. While it would not include the Arab party members directly, this coalition would rely on them to pass essential legislation.

For many in Israel’s Jewish majority, the idea of counting on Arab lawmakers to cast decisive votes triggers deep concerns, ideological and psychological, over the fate of Israel as a Jewish state.

“Most Israelis are Zionists, and they just cannot accept that four anti-Zionist parties would be allowed in the government,” said Michael Milshtein, head of the Palestinian Studies Forum at the Moshe Dayan Center at Tel Aviv University. “There is a deep, psychological fear that they would want to change the basic character of the Jewish state, and while most Jewish Israelis want equality, they just can’t allow the Jewish and Zionist character of the state to be eradicated.”

Netanyahu and other Likud leaders have likened this potential development to a “terrorist attack on democracy,” with one senior minister labeling Arab politicians “terrorists in suits,” accusing them of failing to condemn and sometimes even supporting attacks by Israel’s enemies. Some members of Gantz’s faction have also said they would not support such an arrangement.

There is resistance on the Arab side, too. A campaign promise by Gantz that he would form only a Jewish-majority government was seen as racist and left many in the Arab community offended. And one Joint List party, Balad, has said it will never agree to a Gantz-led government, maintaining that the former general is no different from Netanyahu on the issue of Israel’s continued occupation of the West Bank and its mistreatment of Palestinians.

Many Arab citizens of Israel have close ties with the Palestinian population living in the occupied West Bank and, because of that connection, are viewed by many Jewish Israelis as having dual loyalties. That has not stopped Israel’s Arab citizens from growing as a political force over the past two decades. In the three elections held this past year, their voter turnout increased from 49 percent last April to 59 percent in September to 65 percent last week, lifting the Joint List from 13 to 15 Knesset seats.

“Netanyahu now can’t form a government because of us,” Ayman Odeh, the Joint List’s leader, said in an interview Sunday. “But neither can Gantz. If he wants to be prime minister, then he needs us.”

In September, Odeh, 45, made history by becoming the first Arab leader in three decades to recommend a candidate for Israeli prime minister, getting most of his party to back Gantz.

On Sunday, however, he was still not sure whether this overture would be repeated. It was time, Odeh said, for Gantz to acknowledge publicly the legitimacy of Israel’s Arab population. Odeh’s party also issued a list of demands for Gantz, including repealing the ­nation-state law — which promotes Israel as a Jewish state and no longer treats Arabic as an official language — and a commitment to hold direct peace negotiations with the Palestinians.

Gantz responded Monday by telling Odeh and other Arab leaders that a Gantz government “will serve all of Israel’s citizens, Jews and Arabs alike.” Gantz also held talks Monday with hawkish former defense minister Avigdor Liberman, who in recent days has sharpened his position on removing Netanyahu from office.

“The only thing that puts all these parties in the same ballpark is the understanding that as long as Netanyahu remains prime minister, the political deadlock will continue,” said Dan Avnon, political science chairman at the Hebrew University of Jerusalem.

He said that in theory it was possible for Gantz to form a minority government with outside support from the Joint List. With Netanyahu set to go to trial next week as a defendant in three criminal cases, Avnon said, Blue and White’s hope was most likely that “the fixation of Netanyahu as the ultimate and optimal lifelong leader of Israel could loosen up” and pave the way for others to join their coalition.

Steve Hendrix contributed to this report.