The Prime Minister's Office has sent a letter to the editor of the publication of the predominantly Arab party Balad saying it would combat the activity of any group or individual seeking to harm Israel's "Jewish or democratic character," even if that activity was carried out through legal means.

"The Shin Bet security service will thwart the activity of any group or individual seeking to harm the Jewish and democratic character of the State of Israel, even if such activity is sanctioned by the law," read the letter, sent by the Prime Minister's Office on behalf of the Shin Bet to editor Ala Hlehel.

The letter, published Friday, also said that the Shin Bet would fulfill this task with the "force of the principle of a democracy that defends itself."

Hlehel petitioned the PMO last week following media released information of a closed-door meeting between Prime Minister Ehud Olmert and head of the Shin Bet, Yuval Diskin, in which the latter reportedly described Israel's Arab population as a "strategic threat" to the prime minister.

The two reportedly discussed four documents drafted by groups representing Israel's Arab population which call for a change in Israel's character: "The Future Vision of the Palestinian Arabs in Israel" by the Higher Arab Monitoring Committee, the Musawa oganization's "Ten Point Document," the "Democratic Constitution," by the Adala Center and the yet unpublised "Haifa Treaty."

When Hlehel accused the Prime Minister's Office of "attempting to shut mouths," the Shin Bet responded by saying that there was nothing wrong with the formulation of the documents "unless they reflect or encourage subversive activity," and that the Shin Bet's activity includes foiling such activity on the part of various groups "even if their activity utilizes democratic tools."

Hlehel told Haaretz on Friday that the Shin Bet's response violates the law that regulates its activity, constitutes a blatant breach of its authority, and proves that the "era of military rule imposed upon Arab citizens never ended."

"The Shin Bet is supposed to defend the security of the country, not prevent democratic discussions over the nature of the state... this is very grave and affects all citizens of the state, not just the Arabs," he added.