Benjamin Netanyahu’s main challenger Benny Gantz has rejected the incumbent’s invitation to join him in a “broad, unity government” to break the deadlock after Israel’s fraught election.

“We will not enter a coalition led by Netanyahu,” senior Blue and White leader Moshe Yaalon told reporters at an event attended by Mr Gantz.

Earlier on Thursday, Mr Netanyahu admitted he was unable to form a right-wing government and called on his main rival to join him in a unity coalition.

In a seemingly 180-degree turn, the embattled prime minister personally appealed to Mr Gantz, the country’s former army chief, to join forces in a video statement. His spokespeople later released a joint agreement signed by key Israeli right-wing and ultra-Orthodox parties saying “they will not enter a coalition without each other”.

Mr Gantz had previously ruled out entering into a coalition with Likud if Mr Netanyahu remained at the helm of the party.

Mr Netanyahu, Israel’s longest-serving premier, had been vowing to form a right-wing “Zionist government” led by his Likud party. But partial results and exit polls showed that Blue and White will sweep more of the 120 Knesset seats than Mr Netanyahu’s party.

As of Thursday morning, the partial results were showing that Mr Gantz’s bloc may, in fact, be larger than Mr Netanyahu’s but neither is large enough to secure the 61-seat majority needed to form a government.

Israel election 2019: Netanyahu battles to hang on to power Show all 20 1 /20 Israel election 2019: Netanyahu battles to hang on to power Israel election 2019: Netanyahu battles to hang on to power An Israeli man holding his dog casts his ballot EPA Israel election 2019: Netanyahu battles to hang on to power Chief Rabbi of the Vizhnitz (Hasidic Dynasty) Israel Hager (left), casts his ballot AFP/Getty Israel election 2019: Netanyahu battles to hang on to power Israeli Prime Minister Benjamin Netanyahu and his wife Sara casts their votes AFP/Getty Israel election 2019: Netanyahu battles to hang on to power A man takes a selfie with his mobile phone as he casts his ballot Reuters Israel election 2019: Netanyahu battles to hang on to power An Arab Israeli woman votes during Israel's parliamentary election at a polling station in Kafr Manda near Haifa on September 17, 2019. (Photo by Ahmad GHARABLI / AFP)AHMAD GHARABLI/AFP/Getty Images AHMAD GHARABLI AFP/Getty Israel election 2019: Netanyahu battles to hang on to power Israel's former defence minister Avigdor Lieberman and his wife Ella cast their ballots AFP/Getty Israel election 2019: Netanyahu battles to hang on to power Israeli children accompany their father during Israel's parliamentary election at a polling station AFP/Getty Israel election 2019: Netanyahu battles to hang on to power Blue and White party leader Benny Gantz and his wife Revital vote AP Israel election 2019: Netanyahu battles to hang on to power Israeli Prime Minister Benjamin prepares to vote AP Israel election 2019: Netanyahu battles to hang on to power A family votes in the settlement of Tekoa AP Israel election 2019: Netanyahu battles to hang on to power Ballots lies on a table AFP/Getty Israel election 2019: Netanyahu battles to hang on to power Israel's former justice minister Ayelet greets supporters after casting her ballot AFP/Getty Israel election 2019: Netanyahu battles to hang on to power An elderly ultra-Orthodox Jewish man casts his ballot at a voting station in the city of Bnei Brak during the Israeli parliamentary election on September 17, 2019. (Photo by Menahem KAHANA / AFP)MENAHEM KAHANA/AFP/Getty Images MENAHEM KAHANA AFP/Getty Israel election 2019: Netanyahu battles to hang on to power A mother takes a photograph of her daughter near a ballot box Reuters Israel election 2019: Netanyahu battles to hang on to power Children stand with their relative as they place his vote in a ballot box Reuters Israel election 2019: Netanyahu battles to hang on to power A woman holds her dog's leash as she prepares to vote Reuters Israel election 2019: Netanyahu battles to hang on to power An ultra Orthodox Jewish man casts his ballot during Israel's parliamentary election, at a polling station in Rosh Haayin, on September 17, 2019. (Photo by Jack GUEZ / AFP)JACK GUEZ/AFP/Getty Images JACK GUEZ AFP/Getty Israel election 2019: Netanyahu battles to hang on to power An Israeli woman casts her ballot during Israel's parliamentary election at a polling station in Tel Aviv on September 17, 2019. (Photo by GIL COHEN-MAGEN / AFP)GIL COHEN-MAGEN/AFP/Getty Images GIL COHEN-MAGEN AFP/Getty Israel election 2019: Netanyahu battles to hang on to power Israel's head of the Joint List alliance Ayman Odeh casts his ballot accompanied by his family AFP/Getty Israel election 2019: Netanyahu battles to hang on to power epa07847854 Ultra-Orthodox Jews register at polling station during the Israeli legislative elections, in Jerusalem, Israel, 17 September 2019. Israelis are heading to the polls for a second general election, following the prior elections in April 2019, to elect the 120 members of the 22nd Knesset, or parliament. According to the Israel Central Bureau of Statistics, about six million people are eligible to vote. EPA/ABIR SULTAN ABIR SULTAN EPA

“During the election campaign, I called for the establishment of a right-wing government but to my regret, the election results show that this is impossible,” the prime minister said in his most concessionary speech yet.

“Benny, we must set up a broad unity government, as soon as today. The nation expects us, both of us, to demonstrate responsibility and that we pursue cooperation.”

He then urged his chief rival to meet him “today, at any hour”.

However, the day before, Mr Gantz said he hoped for a “good, desirable unity government” but also ruled out forming one with Likud, citing looming corruption charges against the prime minister. Netanyahu denies any wrongdoing.

Israelis went to an unprecedented second election on Tuesday, after Mr Netanyahu and his right-wing Likud party failed to form a coalition government following a previous vote in April.

Mr Netanyahu’s former ally and ex-defence minister Avigdor Lieberman pulled his right-wing Yisrael Beiteinu party out of the coalition-building process at the last minute.

In this round, Israeli media reported that, with 97 per cent of the votes counted, Blue and White were in the lead with 33 seats, while Likud secured 31.

More devastating for Mr Netanyahu is that his bloc of right-wing and ultra-Orthodox parties currently stands at 55 seats. While Mr Gantz’s centre-left bloc has 57 seats.

The official count on the election commission website has only counted 68 per cent of the votes, but still shows a slim Blue and White lead.

Mr Netanyahu had sought a clear victory with his right-wing partners to secure immunity from three expected corruption trials.

But the results have left him few options to forge a coalition on his own without Blue and White, bar calling for a third election, which would be deeply unpopular among the parties and the electorate.

Yariv Lenin, the country’s tourism minister and a Likud MK, said just before Mr Netanyahu’s statement that the door was still open for negotiations with Mr Gantz, as long as he agrees to withdraw his demand that Likud drops Mr Netanyahu as its leader.

Mr Gantz has made it repeatedly clear he will not sit with Mr Netanyahu – who will face a pre-trial hearing for three corruption cases in the coming months before the country’s attorney general is widely expected to indict him.

Mr Netanyahu is not the only sticking point for a possible broad unity government. During fraught negotiations on Wednesday, he promised his staunchest allies, the ultra-Orthodox parties, he would stick by them.

Blue and White called for a secular unity coalition in the later stages of its campaign. Mr Lieberman, meanwhile, has also called for a secular parliamentary alliance.