Human rights groups announced Monday that they plan to sue Foreign Minister Avigdor Lieberman for libel after he called them "terror groups" on Sunday.
"Your comments constitute mendacious, wild, and thuggish incitement which you dreamed up," the organizations Adalah, Yesh Din, and Breaking the Silence wrote to Lieberman in a letter.
"These are not left-wing and human rights organizations, but terror groups and terror supporters," Lieberman said Sunday after Prime Minister Benjamin Netanyahu announced he would not back a bill establishing inquiry committees to probe the groups.
"All those Adalah, Yesh Din, Breaking the Silence, which provide distorted information, are part of the de-legitimization; all those Marmara activists, who disrupted the IDF's efforts to defend Israel, who handed the names of IDF officers and soldiers to courts across the world and helped Hezbollah with espionage operations."
The organizations are being represented by Attorney Michael Sfard, who responded to the foreign minister's claims.
"My clients are organizations that promote an agenda of defense of human rights, coexistence, and peace, and accusing them of terrorism, espionage, and assisting the enemy is an inexcusable lie," he said.
"With your irresponsible accusations you have transgressed all accepted boundaries of public debate. You published libel in order to hurt my clients, and thus to the best of our understanding committed a criminal offense."
Sfard went on to say that organization heads stopped themselves from filing a suit a few months ago, when Lieberman accused them of assisting terrorists, but after Sunday's comments could no longer abstain.
"Yesterday we realized that you wrongly interpreted our restraint… and that you will not likely stop until someone acts on your comments," Sfard said.
He added that if Lieberman opts to use the immunity granted him as an MK "the Israeli public will understand that you are afraid of the truth". Lieberman's office refused comment on the letter, saying "it isn't necessary to respond to anyone".
Meanwhile initiators of the inquiry committees bill, MKs Danny Danon (Likud) and Faina Kirshenbaum (Yisrael Beiteinu), gathered the 20 signatures required in order to cancel anonymity in the vote on the bill.
It appears the MKs want to shame their right-wing colleagues into voting in favor of the bill, though few legislators believe it will pass.
"I hope members of the Likud don't capitulate to elitist pressure," Danon said. Kirshenbaum explained, "Freedom of vote means each person votes according to his conscience. In such a situation it is important to show the public exactly where the hearts of their representatives are."
Moran Azulay contributed to this report