Israeli Prime Minister Benjamin Netanyahu (C, 1st row) and Avigdor Lieberman (L, 2nd row), former Minister of Defense and the leader of Yisrael Beiteinu party, are seen at the Knesset, the Israeli parliament, in Jerusalem, on May 29, 2019. The Israeli parliament on Wednesday night approved a law for its dissolution, less than two months after the general elections that took place on April 9. The next elections are expected to be held on Sept. 17, 2019. (Xinhua/Gil Cohen Magen)

Israeli Prime Minister Benjamin Netanyahu called on his main challenger Benny Gantz Thursday to form a unity government together, a major development after deadlocked election results put his long tenure in office at risk.

Netanyahu, in a video message, said he preferred to form a right-wing coalition, but the results showed it was not possible.

The stark admission followed Israel's general election on Tuesday that has threatened Netanyahu's status as the country's longest-serving prime minister as he faces possible corruption charges in the weeks ahead.

"During the elections, I called for the establishment of a right-wing government," Netanyahu said in a video message. "But unfortunately the election results show that this is not possible."

He went on to call on Gantz to form a "broad unity government today."

Gantz had not yet responded publicly, but he has repeatedly called for a unity government.

Following Netanyahu's message, at a memorial for the anniversary of the death of ex-president Shimon Peres that both attended, the two men shook hands. It is unclear, however, if Gantz, who has in the past spoken of not wanting to serve in a government with an indicted prime minister, would accept such a government with Netanyahu remaining as premier.

Netanyahu was seeking to seize momentum by announcing his intention to form a unity government and head off attempts to oust him.

Blue and White, a centrist alliance, has in the past sought to appeal to members of Netanyahu's right-wing Likud to abandon him and form a unity government with it. But there has so far been no signal that any Likud members would be willing to do that, and in his speech following the closure of Tuesday's polls Gantz made no such demand.

Official results have not been announced, but Israeli media have reported that Blue and White has 33 parliamentary seats and Likud 31 out of 120 with 97 percent of the votes counted.

Gantz's slim lead, however, gave no obvious path for either party to form a majority coalition.

Ex-defence minister Avigdor Lieberman has emerged as a potential kingmaker, with the reported results showing his nationalist Yisrael Beitenu party with eight seats.