Benjamin Netanyahu, the Israeli premier, is under pressure as arguing between secular and religious partners over the military draft threatens his coalition government.

Army conscription is a divisive issue among Israelis, with the secular majority that regularly carries out military service resentful of the draft exemptions for the rapidly growing ultra-Orthodox minority.

Mr Netanyahu's biggest coalition partner, the secular Kadima party led by a former army chief, this week signalled it may jump ship if the premier failed to pass legislation making more Orthodox men join the army.

But the religious parties that have been among Mr Netanyahu's most loyal political supporters have also threatened to leave if the decades-old draft exemptions of their constituents were cancelled.

At the same time, the arch-nationalist anti-Arab party of the foreign minister Avigdor Lieberman has insisted any new law should compel Israel's Palestinian citizens to carry out civilian service in hospitals or schools.

Israeli Palestinians, also informally exempted from army service, are against having to carry out such duties.

The divisions are widening just weeks before the law allowing ultra-Orthodox exemptions is due to expire at the start of next month, after the country's supreme court ruled them illegal in February.

Mr Netanyahu is under pressure to find a compromise that would allow him to pass new draft rules and keep his coalition intact. Without a new law, the army may be forced to step into the political dispute and decide how many of the ultra-Orthodox to draft.

"This is a big test for Netanyahu," said Abraham Diskin, an Israeli political scientist. "There is good reason to believe that someone may defect from the government, and even that we'll have new elections."

Public pressure is increasing for Mr Netanyahu to make the draft equal for all citizens, with thousands of reservists and supporters expected to protest today in Tel Aviv, pushing a message of "One Nation, One Draft".

The controversy reflects more than his political struggles. It has become an emotional issue because it involves the army, by far the most respected Israeli institution among Jewish Israelis.

The military has long become a gateway for social, political and business connections for Israelis and draft dodging is often viewed with condescension.

Israeli men are obliged to serve in the army for three years, while women join for about a two-year period. Many serve additional decades as reservists.

But most of the ultra-Orthodox are allowed to avoid service to engage in religious studies under a 2002 law that formalised the decades-old exemption.

There are about 1,600 ultra-Orthodox men in the military, including about 400 who serve in combat units.

Experts say many of them joined because they were not accepted into religious studies or strived to acquire skills for a future profession - a rarity among ultra-Orthodox men, who have remained out of Israel's workforce for decades while they study and live on welfare benefits.

About 60,000 ultra-Orthodox men are exempt from army duty.

"The ultra-Orthodox are mainly afraid of the secularisation of their youngsters in the army," said Yair Sheleg, an Israeli expert on the ultra-Orthodox, who make up about 10 per cent of the population.

"They are trying to keep their young people in a social vacuum."

The exemptions have created bitterness among secular Israelis who account for most of the soldiers and claim they bear most of the country's military - and later in life, economic - burden.

Many secular Jews are supporters of centrist parties and are a key target constituency for Mr Netanyahu, as he tries to reduce his political reliance on the nationalists and religious.

In recent weeks, dozens of reservists have joined a protest against the ultra-Orthodox exemptions in Tel Aviv that has drawn high-profile visitors such as the leader of Kadima, Shaul Mofaz.

The controversy is emerging just two months after Mr Netanyahu sealed a pact to add Kadima to his right-wing government, giving it control over 94 parliamentary seats of a total 120 and helping to soften its hardline image.

For Kadima, a key part of the accord was obtaining the premier's commitment to reform army conscription rules.

So far, the premier's effort to reach a compromise has failed.

This week, he disbanded a government-sanctioned, Kadima-led panel aiming to craft a new draft system after the ultra-Orthodox envoy quit in protest and two others left in anger because the recommendations did not include forcing Israeli Arabs to perform community service in lieu of army duty.

Despite being cancelled, the panel still released its recommendations last Wednesday, including one for 80 per cent of ultra-Orthodox men to be mobilised by 2016, either for the army or community service.

Draft dodgers would be fined thousands of dollars and stripped of housing and tax benefits.

Some commentators said Mr Netanyahu dissolved the panel to avoid angering the ultra-Orthodox.

"He needs the ultra-Orthodox for a rainy day, such as if new elections are called and he will need help forming a government coalition," said Neve Gordon, a political analyst.

In the meantime, the call by right-wing legislators to include Palestinian citizens in the new legislation and obligate them to do community service has angered Arab politicians, some of whom have called the plan an "act of war".

Awad Abdel Fattah, the secretary general of the Arab political party Balad, said Israel should first stop the widespread discrimination against Arab citizens.

"We should not dedicate two years of our lives to serve a Jewish state that systematically oppresses us," Mr Fattah said.