Leaders of Conservative Jewry called on Prime Minister Benjamin Netanyahu on Tuesday to condemn the death threat issued last week to the head of the movement in Israel.

While joining a prayer service at Jerusalem’s Western Wall last Sunday, Yizhar Hess, executive director of the Conservative movement in Israel, was approached by an ultra-Orthodox man, who said the following, according to a post published on Facebook: "I will murder you, if I had a knife I’d put it in you here. If I had an ace I’d take it like this, in your head. You’re a heretic. It’s permitted to kill you."

The man who delivered the threat is currently under police investigation.

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In an urgent letter sent to Netanyahu, the Conservative movement leaders implored him to "condemn unequivocally, and in the strongest terms, the verbal assaults and death threats unleashed on the leader of our Israeli movement."

"Your silence in the face of this mounting intimidation and violence against our leaders is tantamount to your tacit approval," they added. "We insist that you come out and publicly issue a statement condemning the violence and intimidation used by the ultra-Orthodox community to suppress our right to worship as Jews at our religion’s holiest sites."

Hess was at the Western Wall last week accompanying Women of the Wall, the multi-denominational feminist prayer group, during their monthly prayer gathering.

The letter sent to Netanyahu was signed by more than 30 Conservative movement leaders, as well as their Masorti movement counterparts, in Israel, the United States, Canada and South American countries. The Conservative movement represents more than 2 million Jews worldwide.

The assault on Hess and similar incidents, the letter warned, "serve to widen the gap between Israel and Jewish communities abroad, making them wonder whether Israel still represents their Jewish values."