Israeli Knesset member Anastassia Michaeli threw water over her Arab colleague, Raleb Majadele, following a heated argument.
The incident occurred during a Knesset Education, Culture and Sports Committee debate on an Israeli-Arab school that took its students to a human rights march early in December.
The Arara High School, from the Negev area, was criticised by the Education Ministry for allowing its students to participate in a human rights march in Tel Aviv. The school provided transportation for the students to the march as part of an assignment for their civics class.
"What better way to express civic involvement and internalize the material... it was a celebration of human rights," said one of the school's teachers.
The argument erupted after Majadele expressed support for the principal of the school, a sentiment which angered Michaeli, who is from the nationalist party Yisrael Beiteinu.
"You are marching against the state," she screamed at Majedele, who responded: "Shut up."
"She won't shut me up," he added. "This is not Yisrael Beiteinu. The issue of fascism won't stop here - I intend on taking this debate to other Muslims who will serve as an example for the State of Israel... Fascism will not be allowed to take over the house."
At one point, Michaeli appeared about to leave the room in order to calm down, but instead poured a glass of water which she threw over Majadele. She then stormed out of the room, while an unidentified Knesset member is heard calling her "crazy".
Michaeli has been involved in other confrontations with Arab colleagues. During a parliamentary debate about the Gaza flotilla last June, she attempted to forcefully remove Knesset member Hanin Zuabi while he was making a speech.
Zuabi had participated in the 2010 attempt to break the Gaza blockade, which ended with the deaths of nine human rights activists.
Michaeli was reprimanded for physically threatening a colleague, while Zuabi was sanctioned for his part in the flotilla.
She has also reportedly received death threats for her recent introduction of a bill to ban the use of loudspeakers in making the Islamic call to prayer.