New data on the low share of the Charedi community in the Israeli workforce has re-ignited the rift in secular-ultra-Orthodox relations. And while elections are not expected to take place for at least three years, it is already clear that a number of parties will be eager to campaign on this issue.

The writing has been on the wall for years but now, a series of reports has been suddenly released on the Charedi contribution to the economy and national defence, capturing the public's imagination. One study compiled by the Industry and Trade Ministry revealed that only 43 per cent of Charedi men and women are employed, compared to 72 per cent in the secular sector. Among men, the proportion is even lower, with only 37 per cent employed.

Wages for Charedi workers are around 30 per cent lower than their secular counterparts as few of them have academic and professional qualifications. As a result, the average Charedi income is just half that of a secular household, despite having on average almost three times as many children.

In the absence of wages, Charedi families subsist to a large extent on national insurance payments and yeshivah stipends. Another recent study showed that for the first time, over 100,000 Israelis study in yeshivahs financed at least partly by the state. Sixty thousand of them are of compulsory military enlistment age, yet have deferred their service indefinitely.

Senior IDF officers have repeatedly warned in recent months of an impending shortage of soldiers.

These figures were pounced on by the mayor of Tel Aviv, Ron Huldai, who in a widely reported speech this week, blamed the state for "fostering whole communities of ignorant separatists whose numbers are growing at a sickening rate".

Mr Huldai called upon the "silent secular public" to revolt.

Charedi politicians responded that the reports and Mr Huldai's speech were "an organised campaign of incitement against an entire community". They demanded that the state do not "interfere" with their education system, which is "the Jewish people's only guarantee of continuity".

On one detail, at least, they are not wrong. The spate of reports is not coincidental. A loose coalition of political parties and public pressure groups have identified this issue as the new rallying call for the dispirited centre and left. Advisors to Kadima leader Tzipi Livni have confirmed she is planning to run the next election campaign with a call for "an end to blackmail".

Star columnist Yair Lapid, who is widely expected to enter politics, has also been focusing much of his writing lately on this subject.

Statistics such as those included in another report, which predicted that by 2014, 18 per cent of school children will be Charedi, twice the proportion of their community in the general population, can be expected to appear more and more in the secular press.

Having failed to gain power on issues of war and peace, the Israeli centre-left hopes that it can succeed next time by scaring voters with the rising tide of the "parasitical" Charedim.