An impending crisis over conscripting ultra-Orthodox Jews into the Israeli army is threatening to undermine Israel's government and split the country.

Public opinion on the issue has shifted dramatically in Israel after two years of war, and this is now perhaps the most explosive political risk facing Prime Minister Benjamin Netanyahu.

Lawmakers are currently considering a draft bill to end the exemption granted to ultra-Orthodox men enrolled in full-time religious study, established when the State of Israel was declared in 1948.

That exemption was ruled illegal by Israel's High Court of Justice almost 20 years ago. Temporary arrangements to continue it were formally ended by the court last year, forcing the government to begin drafting the community.

Some 24,000 draft notices were issued last year, but only around 1,200 ultra-Orthodox - or Haredi - draftees reported for duty, according to military testimony given to lawmakers.

Tensions are erupting onto the streets, with lawmakers now debating a new draft bill to force ultra-Orthodox men into military service alongside other Israeli Jews.

Two Haredi politicians were targeted this month by some extreme ultra-Orthodox protesters, who are furious with parliament's discussion of the proposed law.

These arrests have sparked the creation of a new messaging system called Black Alert to spread word quickly through ultra-Orthodox communities and summon protesters to prevent arrests taking place.

The push to conscript more ultra-Orthodox also triggered a vast protest by tens of thousands of Haredi men in Jerusalem last month - with the issue seen by many as part of a wider conflict around the identity of the Jewish state, and the place of religion within it.

The ultra-Orthodox population has more than doubled its share of Israel's population over the past seven decades, and now accounts for 14%. What began as an exemption for several hundred religious students became, by the start of the Gaza war, a cohort of some 60,000 men left out of the draft.

Despite the evolving landscape, the underlying tensions regarding religious duty versus national service continue to create a rift within Israeli society, further complicated by Netanyahu's fragile political alliances and impending elections.