RAMAT HASHARON, Israel (Reuters) - In dozens of northern Israeli towns and villages, evacuated under fire from Lebanon's Hezbollah group in parallel with the Gaza war, officials hope daily rocket warning sirens will give way to school bells when the academic year starts on Sept 1.

That ticking clock has become a subject of open disagreement within Prime Minister Benjamin Netanyahu's cabinet, testing its cohesion and credibility.

Of 60,000 civilians relocated from northern Israel at the outset of the war, 14,600 are children, scattered in temporary kindergartens and schools, or premises repurposed as makeshift day-care or classes, throughout the country's interior.

Education Minister Yoav Kisch said Israel is spending $38 million building new kindergartens and schools just out of rocket range in the north, which can take children if their original schools are not yet safe and ready by Sept. 1.

If the new buildings turn out not to be needed, other uses can be found for them.

"I'm hoping that this investment will not be used for the kids that live on the border," he told Reuters in an interview.

It would take at least a month to prepare the orphaned northern schools, some of which are in rubble-strewn and dilapidated communities, for next year's intake of pupils.

"So if we are going to see a solution by Aug. 1, we know that we can start on Sept. 1," he said. Failing that, "we're going to shift all our focus on to the other option".

A LIMIT THAT WE PASSED

Dislocated and hard-put to do homework at the cramped accommodation provided to their families by the state, many of the pupils from the north are slipping, teachers say. Their high-school drop-out rate can reach 5%, according to Kisch - around double the national average.

Some of their parents are looking to resettle permanently, giving up on ever returning to their battered hometowns.

"I'm not sure that all the citizens of Kiryat Shmona will go back to Kiryat Shmona," said Ofer Zafrani, principal of the border city's Danziger High School, which relocated to a row of converted offices atop a multiplex cinema outside Tel Aviv.

"We understand this is the price we need to pay," he told Reuters as pupils milled noisily around him. "But I think that there is a limit that we passed. It's too much."

In the south, even in communities alongside the Gaza Strip, some Israeli families have been able to return home as their armed forces operate across the fence to suppress rocket fire. Zafrani said citizens in the north need a similar chance to go home.

"We must be back - and not only be back, but there has to be a solution for the situation for the north, like the south, so that we will feel safe," Zafrani said.

In Gaza, eight months of Israel's campaign to eliminate Hamas have ravaged the enclave's education system.

TWO FRONTS, INTERTWINED

The exchanges of fire on Israel's northern front, in parallel with the war in Gaza, have so far been contained without escalating into an all-out cross-border war in Lebanon, like the one Israel last fought against Hezbollah 18 years ago.

But scores of people have been killed on both sides. On the Lebanese side, 90,000 civilians have also been evacuated, around a third of them children, most now registered in new schools, according to U.N. figures.

Israel has threatened possibly imminent escalation to an invasion of Lebanon - while also leaving the door open to a U.S.- or French-mediated truce which would keep the Iranian-backed fighters away from the border.

Touring the frontier on May 23, Netanyahu said Israel has "detailed, important, even surprising plans" for driving Hezbollah back, "but we don't let the enemy in on these plans".

His refusal to get into details or dates was a swipe at Netanyahu's political rival turned war cabinet partner, Benny Gantz, who has threatened to bolt the emergency coalition this week over what he says is a lack of clear strategy.

Gantz also visited the north at the same time as Netanyahu, in a separate armoured cavalcade.

"I call on the government to commence preparations, already today, for us to return residents safely to their homes by September 1, whether through force or an accord," Gantz said. "We must not allow another year to be lost in the north."

The two fronts are intertwined, as Hezbollah says it will keep shelling as long as Israel's war on Palestinian Hamas fighters continues. Both militant groups are allies of Iran.

Promoting a Gaza truce, U.S. President Joe Biden has dangled a knock-on benefit of quiet in south Lebanon.

But some Israeli officials fear being boxed-in: once northern residents return, Hamas might see an opportunity to strike again, calculating that Israel will not want to retaliate lest Hezbollah attacks resume and necessitate fresh evacuations.

Meanwhile, Israeli education officials say they are also preparing for a far more disruptive scenario: full-on war with Hezbollah. That would be likely to put all of Israel under threat from the group's rockets. Then, Kisch said, most of the country's schools would be shuttered as civilians take shelter.

"If it will be a long process, there will be homeschooling as well," said Kisch, who was Israel's deputy health minister during the COVID lockdowns and remote-learning ordinances.

"But I hope that we'll be able, with a very strong and effective war, to get this threat out of our way very fast."

(Writing by Dan Williams; Editing by Peter Graff)

By Dan Williams and Emily Rose