Opposition party leaders on Thursday condemned the newly merged Likud-Yisrael Beytenu party list as an extreme, radical right-wing party and called for the formation of a center-left bloc to counter it in the upcoming elections.

Labor Party leader Shelly Yachimovich implored center-left parties to unite in order to defeat Benjamin Netanyahu and Avigdor Liberman’s “Likud-Beytenu” super-faction.

“The union of Liberman and Netanyahu founds a new, extremist, racist party. It doesn’t even occur to me to join this party” in a post-election coalition, Yachimovich said, moments after Netanyahu and Liberman announced their merger.

“I call on voters who just lost their political home to join the Labor Party and not allow a Netanyahu-Liberman party to rule.”

“It’s a great opportunity for us in the center,” senior Labor MK Isaac Herzog told Channel 10. The new alliance “will be an extremist North Pole, and we’ll be the leading centrist force,” he said.

Kadima party leader Shaul Mofaz, briefly Netanyahu’s coalition partner between May and July this year, derided the Likud-Yisrael Beytenu merger and called the united list a “radical, extreme party” that “doesn’t believe in the peace process.” Mofaz also called on center-left parties to “leave your egos aside” and unite to defeat Netanyahu’s super-party.

Yesh Atid party chairman Yair Lapid described the merger as a sharp right turn for the Likud party. Likud, he said, was now a party of far-right radicals like Liberman and hawkish Likud sub-faction leader Moshe Feiglin.

Despite Yachimovich’s plea, Lapid dismissed the possibility of a center-left union with the Labor Party, saying Labor has taken a sharp left-hand turn. He reiterated his party’s commitment to a centrist policy with which he said the majority of Israelis associate.

“Netanyahu went with the extreme right. Yachimovich broke to the left, and the reasonable and moderate Israeli majority for some time hasn’t identified with the parties of yesterday,” he said.

Former Kadima leader Tzipi Livni, who has not yet announced her possible return to politics, said Netanyahu’s move made it clear “that now the elections will be between a radical, isolated state run by Liberman and Netanyahu, and a sane, Zionist state.”

“I was born in the Herut movement. I know what values Likud is supposed to represent — and has abandoned. The election doesn’t have to be between fringes and radicalism, rather between radicals and a Zionist center that believes in a Jewish, democratic, and balanced Israel,” she said.

Likud minister Yisrael Katz told Channel 10 that Likud party members smiled on the merger and received it with “great affection.”

Left-wing Meretz party leader Zahava Gal-on called a potential Netanyahu-Liberman government radical and extremist, and coined the term “Biberman government” to describe the merger.

She said the hawkish Liberman, as foreign minister, had isolated Israel diplomatically, and that the new partnership meant the now-”settler-esque” Netanyahu was completely throwing in his lot with the West Bank settlements.

“This sends the message that the governing bloc will continue to incite against the left and against the Arabs,” she said. “The fascism in the Likud back benches is now — with the Liberman merger — coming to the fore.”

The Shas party reacted to the surprise merger — which a Channel 2 pundit speculated could exclude the religious party in a future coalition government — by saying, “today it’s clear that the Likud party doesn’t represent the Mizrahi community.”

One of the leaders of the Shas ultra-Orthodox party, Eli Yishai, said he was “completely taken by surprise” by what he carefully called an “exciting” development. He speculated it might prompt parties on the center-left, including Kadima, Labor and Yair Lapid’s new Yesh Atid, to follow suit and run together.