Tuesday's Knesset decision to revoke three key parliamentary privileges from Balad MK Hanin Zuabi is cause for concern. Though the move was adopted in the plenum, there were few participants present, and the extremists - led by MK Michael Ben Ari of National Union - managed to push it through unimpeded.

It seems elected officials no longer understand the meaning of freedom of expression. If they believe Zuabi broke the law, the Knesset's legal adviser is supposed to handle the matter. If this is not the case, even if her opinions are considered offensive, her colleagues must resolutely support her right to have them heard.

It is difficult to ignore that Zuabi, like other Arab MKs, is enthusiastically participating in acts of extreme provocation. It could even be assumed that she profits to some degree from being marked as an enemy of the people, but this is destructive to the Arab population in particular, and to Israeli society on the whole. It certainly does not justify revoking substantive privileges to which Zuabi's position entitles her.

But in an atmosphere of overheated rhetoric directed at Arab MKs, the decision is not surprising. Rightist MKs are continuously planning new boycotts and excommunications: The interior minister considered stripping Zuabi of her citizenship because of her participation in the Gaza aid flotilla, and Ben Ari and Carmel Shama (Likud ) proposed prosecuting and stripping the parliamentary immunity of Arab lawmakers who had visited Libya.

This week the government approved the Bishara bill, a problematic measure that makes it possible to revoke the pension rights of an MK defined as a "traitor," even before he or she has been convicted . In addition, the chairman of the Economic Affairs Committee, MK Ofir Akunis (Likud ), declared he will not support bills brought by MK Ahmed Tibi (United Arab List-Ta'al ) on the grounds that Tibi assisted the Libyan aid flotilla. Akunis went further, threatening Tibi: "We'll deal separately with your presence in the Knesset."

It's a shame Knesset Speaker Reuven Rivlin, who scolded Akunis and sharply criticized the decision against Zuabi, ultimately abstained from the vote, thereby turning his protest into empty words. All of these developments symbolize the moral weakness of the 18th Knesset, the damage it is inflicting on freedom of speech and the danger it poses to democracy in Israel.