Za'atara is only supposed to take on the role of Haifa deputy mayor in two and a half years for half a term as part of rotation agreement with Meretz faction chairman Rabbi Dubi Haiyun.
Za'atara, an Israeli-Arab, was selected deputy mayor after he joined the municipal coalition.
But over the past few years, he has led many demonstrations during which Palestinian flags were waved.
In a recent demonstration three months ago, Za'atara told Yedioth Ahronoth that he is protesting "against the siege imposed on Gaza, the killings of unarmed Palestinian protesters, and the oppression and intimidation policy."
Speaking on the panel at Bar-Ilan University three years ago, he sparked ire by comparing the Islamic State (ISIS) to the Zionist movement.
"Where did they (ISIS) learn these crimes? Look up what the Zionist movement did in 1948. Rape, looting, murder and massacres were committed here," he claimed.
When asked whether Hamas is a terror organization, the Hadash party member replied, "No. An occupied nation has the right to resist the occupation."
Haifa's residents are bewildered by Rotem's choice to add Za'atara—whose faction gained only two seats in the municipal elections—to the municipal coalition rather than the Likud faction, which received three seats.
"It's a disgrace a man who supports Israel's worst enemies is appointed as the deputy mayor," one of Haifa's residents said.
In response, Za'atara told Yedioth Ahronoth: "I'm not taking back what I said in the past. Those sitting with us in the coalition seek to incite and fan the flames of hatred against me, my party and the Arab sector.
"I understand this is part of local politics. My main goal is to promote coexistence in Haifa, while working to improve the city's education, housing and traffic problems," he explained.
"I suggest those who speak ill of me to judge me by my actions to promote our joint life and equality in Haifa," he added.
The Haifa municipality is yet to comment on the matter.