Israel’s popular ex-army chief broke weeks of silence to launch his long-awaited election campaign, promising unity in the country and an end to corruption in a speech where he slammed Benjamin Netanyahu as “no king”.

To the chants of “who is that? The next prime minister”, the blue-eyed paratrooper formally declared his candidacy and tore into Israel’s prime minister, saying that the current government “sows division and incitement”.

Lt Gen Gantz, who is currently Netanyahu’s biggest rival, also made reference to the three graft cases against the prime minister which are casting a long shadow over the right-wing leader’s chances of being re-elected. Israel’s attorney general Avichai Mendelblit is expected to file an indictment against the premier within the coming weeks.

“Netanyahu is no king ... A prime minister cannot preside over Israel when an indictment has been filed against him,” Gantz told the cheering Tel Aviv crowds on Tuesday night.

“No Israeli leader is a king … The government we will form will be a national government and not a monarchy,” he added.

If Mr Netanyahu is re-elected in the April polls he will be Israel’s longest-serving prime minister.

However, he may also become the first Israeli leader to face trial while still holding office.

According to leaks in Israeli media, the state prosecutor is likely to recommend Mr Netanyahu be indicted in case 4,000 or “Bezeq” as it is known, named after a telecommunications company he supposedly awarded regulatory favours to.

He may also face trial in the other two cases, in which police have argued that he received expensive gifts from wealthy friends, and in which he allegedly negotiated a deal with the Yedioth Ahronoth newspaper for better coverage.

Mr Netanyahu already had to call snap elections seven months early after he was left trying to rule the country with a paper-thin one-seat majority in Israel’s 120-seat parliament, when key coalition partner and defence minister Avigdor Lieberman quit in November over the prime minister’s refusal to go to war with Gaza.

Mr Netanyahu was quick to respond to his rival, calling his speech “ridiculous” and labelling Gantz as “weak left”.

Gantz’s campaign responded to the remarks, with a spokesperson saying: “Thank you for the last 10 years, we’ll take it from here.”

Lt Gen Gantz served as chief of staff between 2011 and 2015 and led Israel’s offensive into Gaza.

He formed the Israel Resilience party and launched his election bid in December, but until Tuesday had kept silent on his political affiliations or plans.

Benny Gantz (right) former minister of defence Moshe Ya’alon gesture supporters during a campaign event (Getty) (Photo by Amir Levy/Getty Images)

Just ahead of his first campaign speech on Tuesday, he announced he had merged his party with that of ex-defence minister and also former chief of staff Moshe Ya’alon.

General Ya’alon, who served as Netanyahu’s defence minister from 2013 to 2016 and was Gantz’s boss, joined him on stage Tuesday night but revealed no details about their partnership.

Instead Lt Gen Gantz gave a wide-ranging speech which looked to appeal to all segments of Israeli society in an apparent bid to draw in votes from both the right and the left.

Playing on his security credentials, the ex-army chief spoke of leading fighters across enemy lines and answering the phone in the middle of the night. He vowed never to give up the occupied Golan Heights, to protect the settlement blocs in the West Bank and threatened Iran’s president Rouhani, as well as Hezbollah leader Hassan Nasrallah.

He concluded the segment warning Hamas, the militant group that governs Gaza, that Ahmed Ja’abari, the Hamas chief who was killed under Gantz’s orders, that he “wasn’t the first and won’t be the last”.

However, he also vowed to uphold gay rights and introduce civil marriage, to deepen a partnership with the ultra-Orthodox, and to work to support the Arab population and the Druze. He also said he would allow humanitarian assistance into Gaza.

Some of those who turned up not knowing what to expect said they left feeling convinced of his candidacy.

I came here to hear him and I came out supporting him Tamar Ben Porat, Gantz supporter

“I came here to hear him and I came out supporting him,” said Tamar Ben Porat, 56, a lawyer and women’s rights activist from central Israel.

“He could bring votes from right, the centre and the left and I’m happy he managed to get an understanding with Ya’alon – they have both expressed their views on corruption.”

She said people were fed up the current leadership because of the graft cases against Mr Netanyahu and were looking for a prime minister to help build peace with the Palestinians rather than peddling wars to get votes.

“Netanyahu’s government is one of separation and hatred. We need a leader to reunite the people,” she added.

A group of 19-year-olds, who were looking forward to voting for the first time, agreed that Gantz may be able to unite the right and left and build peace with Israel’s neighbours.

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“He does convince the youth – what we want to see a new face. He talks a lot of peace which the right don’t anymore,” said Yaniv Cohen.

“He has been very clever with his campaign – he sneaks ideas from the left and puts them in the centre. I believe he could unite people,” he added.

His friend Yoav said that his biggest hope was that Gantz would be able to reignite the stalled peace process.

“I believe this is the last chance to make peace with the Palestinians and if we don’t act now something bad will happen,” Yoav said.