There is a new battleground for Israel's secular-religious tensions: the advertising sales room.

The Orthodox anti-missionary charity Yad L'Achim is suing Army Radio for refusing to air its advertisement.

The Supreme Court has given the station an April 11 deadline to explain why it refused to air a 27-second advertisement which urged listeners to not let missionaries "mess with your soul" and to "protect your proud Jewish identity".

Army Radio considered the advertisement too controversial. "The subject was examined by the station's legal advisers and is not suitable for broadcast," said spokeswoman Tali Tenenbaum.

Rabbi Aaron Rubin, a leader of Yad L'Achim, insisted that the message was a mainstream one, in the contexts of both Israel where opposition to missionaries is widespread, and world Jewry where organisations across the spectrum try to boost Jewish identity. "I don't think any Jewish organisation around the world would find this controversial - a call to be proud to be Jewish and keep your Jewish identity," he said.

However some religious rights campaigners are siding with Army Radio. Anat Hoffman, executive director of the Israel Religious Action Centre, thinks that in its day-to-day activities Yad L'Achim verges on "incitement" against missionaries, and as such deems Army Radio's decision fair.

The court's demand that Army Radio should explain itself comes hot on the heels of a ten-day standoff between the Supreme Court and advertising executives at the Charedi newspaper Yated Neeman.

In January, the Supreme Court outlawed buses with enforced segregation along gender lines. Judges demanded that the bus company Egged, which operates dozens of segregated lines, informed the Charedi public that separate seating is now voluntary. It was obliged to place advertisements in the Charedi media to this effect by February 6, but the daily Yated Neeman - one of the leading voices in favour of segregated busses - refused the advertisement until it caved in on February 17.