An ultra-Orthodox Jew looks at an election billboard poster in Russian that translates to 'Death Sentence to Terrorists,' and underneath, 'Right On Lieberman' in Jerusalem, 01 March 2015. (EPA/JIM HOLLANDER)

Avigdor Lieberman, Israel's foreign minister and the head of a right-wing, Israeli nationalist party, is known for his fiery rhetoric. But he possibly crossed a line during an election rally in the city of Herzliya on Sunday.

"Whoever's with us should get everything," Lieberman said, in reference to the loyalty of Israeli Arabs, who make up some 20 percent of Israel's population. "Those who are against us, there's nothing to be done – we need to pick up an axe and cut off his head. Otherwise we won't survive here."

Lieberman, the head of the Yisrael Beitenu party, may argue he was speaking in biblical metaphors -- his comments carried allusions to the Book of Esther, reports Haaretz. But they are deeply provocative, and reflect Lieberman's known antipathy for the Israeli Arab population.

The foreign minister's comments in the past have led critics to accuse him of racism. These include his calls last year to boycott Arab businesses that had shut their doors in protest of Israel's bombing campaign in Gaza, as well as a proposal made last November suggesting Israeli Arabs be given "economic incentives" to leave their homes in Israel for the West Bank.

Unlike some other politicians on Israel's right, Lieberman is staunchly secularist. His brand of nationalist populism is anchored among Israeli Jews who emigrated from countries in the former Soviet Union, where he himself was born.

Lieberman's reference to beheading is particularly garish given the wider context of the region. The jihadists of the Islamic State have carried out the grisly act on hostages throughout the past year in the war zones of the Middle East. Israeli Prime Minister Benjamin Netanyahu singled out the group's savagery in a speech last week in Washington, equating its worldview with that of Iran, his main geopolitical foe.

Netanyahu's Likud party even ran a campaign ad warning that, should his centrist and center-left opponents win in upcoming elections this month, the door will be open for the Islamic State to infiltrate the Jewish state. Lieberman's party could once more partner Likud in a coalition government after Israelis go to the polls.

After Lieberman made his controversial remarks, an irate Arab Israeli legislator demanded an investigation into the comments and labeled Lieberman as "Jewish ISIS," referring to another term for the Islamic State.

Related links