JERUSALEM, March 28 (Allyn Fisher-Ilan/Reuters) - Israel passed a law on Monday that eases the process of revoking citizenship in a step denounced as a move to threaten primarily its Arab minority.

The amendment to a so-called Citizenship Law was the latest in a list of parliamentary measures taken this past month that civil rights activists denounce as undemocratic but Israeli rightists see as essential to the Jewish state's defense.

The measure, which passed by a vote of 37 to 11 after a stormy debate, empowers Israeli judges to deny citizenship privileges to anyone convicted of espionage or committing violence with nationalist motives.

An official explanatory text said that the law was intended to expand the possibility of denying citizenship and empowers the court that convicts someone of crimes of acts of terror, espionage or treason to be stripped of citizenship.

Israeli Foreign Minister Avigdor Lieberman, whose ultra-nationalist party sponsored the measure, proclaimed victory after the vote, saying he had fulfilled a pledge to voters to crack down on any citizen who sides with the enemy.

Israel's Association for Civil Rights issued a statement in protest saying that in a democracy you don't deny citizenship and that the measure sends a humiliating and discriminatory message that citizenship for Israeli Arabs is not automatic.

Israel has seldom revoked citizenship privileges in the past, and the measure's passage now seemed symbolic of how increasingly Israeli rightists see the nation's Arabs as well as leftist critics as a threat to their embattled country's future.

Israeli Arabs, who make up about a fifth of Israel's population, are descendants of Palestinians who remained in what is now Israel when hundreds of thousands were driven away or fled in a 1948 war over Israel's establishment.

Unlike Palestinians living in territory Israel captured in a 1967 war, Israeli Arabs are fully enfranchised though many complain of discrimination. A small number of them have been charged with crimes linked to Palestinian militancy.

DEMOGRAPHIC WAR

Arab lawmakers, who number about a dozen in Israel's 120-member Knesset, gave angry speeches against the measure.

This is another law intended to wage demographic war against us, Hanna Sweid, of the Democratic Movement for Change, said, referring to those Israeli ultra-nationalists who have voiced fears of Jews being outnumbered by Arabs in the future.

Punctuating the debate was an argument between right-wing lawmaker Anastasia Michaeli and Arab legislator Afa Aghbaria who called her a shiksa, a Yiddish word for a non-Jewish woman -- challenging her Jewish credentials which entitled her to automatic Israeli citizenship.

Michaeli, a Russian immigrant, is a convert to Judaism.

Israel's parliament has passed and debated a list of measures denounced as undemocratic and anti-Arab this month by civic rights campaigners.

A law passed a week ago would penalize those engaging in public denunciations of Israel's founding as a nakba, the Arabic word for catastrophe.

Yet another permits small communities to exclude anyone seen as unsuitable from their midst, including Arabs who constitute a majority in some of the regions where the law applies.

A proposal to investigate funding for left-wing groups was shelved, though, after Prime Minister Benjamin Netanyahu stepped in, answering critics who called it a blow to free speech.

Also last week, ultra-nationalist lawmaker Danny Danon held a hearing to upbraid the Jewish-American J-Street, saying the group, which criticizes Jewish settlement-building in occupied land, should be shunned as pro-Palestinian, not pro-Israeli.

David Gilo, a J-Street leader, rejected the charge. We are Zionists and care about Israel, Gilo told the Knesset panel.

(Editing by Mark Heinrich)