The rapid increase in the number of Jewish schools over the past decade or so, and the possibility of more to come, has once again raised the question: will there be enough Jewish teachers to staff them?

Next week, 40 teachers will graduate from training schemes at the London School of Jewish Studies - quite possibly the largest batch in its history.

But the challenge remains to ensure that all teachers in mainstream Jewish school have a recognised education qualification.

Rabbi Raphael Zarum, dean of LSJS, said that "from our statistics, less than 50 per cent of Jewish studies teachers are qualified".

Although many might be naturally talented educators, everyone "dramatically improves" from taking part in a training course, he argues.

The job requires specific skills: to know how to differentiate between children of different ability levels in a class for example, or how properly to assess their work. "We are trying to professionalise the field of Jewish education," he said.

As the school network expands, there could be as many as "50 new posts in Jewish studies needed in the next 10 years," he said.

While some of the new LSJS graduates will specialise in Jewish studies, many have trained as general class teachers or in other subjects.

But it takes more than Jewish studies staff to create the Jewish ethos of a school.

Teachers have to be equipped to take part in all kinds of activities which contribute to Jewish programming, "from assemblies to special pre-chagim events", he said.

LSJS offers different options to qualify but there is one condition: students must have a degree. That is potentially an obstacle for religious studies staff who have come straight from yeshivah or seminary without going to university.

But the LSJS BEd course, which can be taken part-time, now provides a suitable degree track.

Dr Zarum said: "We're now planning to open a cohort in Manchester as well. We have about 15 people who have signed up for the degree. But the problem is money. We have to find scholarships for them."

The £3,500 annual fees are beyond the pockets of students, young teachers or the schools which are increasingly under financial pressure, he argues.

Whereas some institutions can turn to successful alumni for support, the graduates of LSJS are teachers and rabbis, who are generally not in high income brackets.

Backing teacher training is a way for the community to prove that it values teaching as a profession.

"I'm from a Yemenite tradition," Rabbi Zarum said, "where if a teacher is called to the reading of the Torah, everyone stands up. That shows the respect for teachers."