The bitter struggle between religious and secular Jews in Israel heated up on Tuesday with a courtroom battle over military exemptions for Orthodox seminary students.

"The crux of this high court petition is to force the minister of defense to declare a reasonable quota beyond which the military would not be able to discharge seminary students from army service," said parliamentarian Amnon Rubinstein.Under an agreement dating from the early days of the state, the Israeli army exempts from conscription men studying full time at Jewish seminaries. Other Israelis, men and women, are drafted at the age of 18.

Rubinstein, another member of his left-wing Meretz party, and a group of army reserve officers filed the petition which is to be heard before an expanded panel of 11 justices.

"The practice is being abused because people who want to be rid of the army service, all they have to do is register in the seminary," Rubinstein told Reuters.

"What started as an exemption of a few hundred students has reached frightening proportions. We are now dealing with 30,000 ultra-Orthodox young men who are exempt," he said.