(An ultra-Orthodox Jewish man sleeps as others study at a Yeshiva, a Jewish seminary, in Jerusalem's Mea Shearim neighbourhood May 24, 2012. REUTERS/Ronen Zvulun)

One of the earliest decisions the Zionist leaders of the new state of Israel made in the late 1940s was to strike a deal with ultra-Orthodox rabbis from Eastern Europe to help preserve a traditional Jewish practice almost wiped out in the Holocaust.

Seeking political support from the rabbis, Prime Minister David Ben-Gurion agreed to exempt about 400 pious students from military service so they could devote themselves to lifetime study of the main Jewish scriptures, the Torah and the Talmud.

It seemed a small concession at the time.

Over six decades later, the once threatened ultra-Orthodox are a fast-growing underclass making up about 10 percent of Israel’s population. The original handful of students has ballooned to about 60,000 men supported by state handouts, occasional work and donations from family and friends.

Most ultra-Orthodox, whose men stand out due to their old-fashioned beards, black hats and long coats, say nothing should change. All men who want to devote their lives to Torah study, their rabbis say, should be able to do so.