JERUSALEM: A controversial Israeli law which allowed ultra-Orthodox Jews to defer military service, is to expire on Tuesday, leaving a legislative hole which could technically see them called up en masse.

When the 2002 Tal Law expires at midnight, conscription will be guided by previous legislation, meaning that all 18-year-old Israelis, including the ultra-Orthodox, will be compelled to enlist -- unless they are specifically exempted by the defence ministry.

Israeli Defence Minister Ehud Barak was to release a statement on the issue later on Tuesday, giving the military fresh orders in light of the expiry of the law.

In February, Israel's High Court ruled that the Tal Law was unconstitutional and must be rewritten, prompting calls for a fairer system which would impose conscription or some other form of national service on the ultra-Orthodox as well as on Israel's Arab minority.

But the question of how to reword the law has sparked deep divisions in the right-wing coalition of Israeli Prime Minister Benjamin Netanyahu, which failed to push through new legislation before the parliament broke up for its summer recess.

The centre-right Kadima party pulled out of Netanyahu's ruling coalition two weeks ago, just 70 days after joining it, saying that his draft legislation did not go far enough.

Party leader Shaul Mofaz said he was pulling out over Netanyahu's refusal to accept the conclusions of a committee headed by Kadima MP Yohanan Plessner.

The departure of the 28-seat party, the largest in the 12-seat parliament, reduced Netanyahu's overwhelming majority of 94 to 66 MPs.

Israel's Arab youth have traditionally been exempted from military or national service by means of an unwritten Israeli policy.

But when parliament reconvenes in October after its summer break, attempts to push through fresh legislation compelling both Arabs and the ultra-Orthodox to complete some form of service, are likely to begin again in earnest.