Religious MKs were enraged after a High Court ruling Tuesday ordering the Interior Ministry to register homosexual couples wed abroad as married.
The panel, made up of seven High Court Justices headed by retired Supreme Court president Aharon Barak, ruled unanimously.
"I think every thinking person in Israel and the Jewish world is horrified [at the decision]," MK Moshe Gafni (UTJ) said in response to the ruling.
"In addition to all the troubles we all have, this is added - the family unit is being completely destroyed," Gafni continued. "Some will object, and some will let it pass quietly. [Aharon] Barak is leaving us a parting gift that signifies the destruction of the family. There were also courts in Sodom and Gomorrah."
"Why is the court interfering in all aspects of our lives?" Gafni continued.
MK Zevulun Orlev (NU-NRP) denigrated the decision as "paganism," and said it "tore the last mezuza off the door."
MK Uri Ariel (NU/NRP) also slammed the decision and announced he would launch a Knesset discussion on the matter.
"The High Court has gone a step too far, and the Knesset won't let them get away with it," he said.
In 2005, the Housing and Construction Ministry decided to grant same-sex couples with at least one child housing benefits, but same-sex marriage - and its legal benefits - remained a non-starter.
Other MKs expressed optimism over the ruling.
MK Haim Oron (Meretz) welcomed the decision, while his party colleague Zehava Gal-On called for Interior Minister Roni Bar-On to implement the change immediately.
Meretz chairman Yossi Beilin supported the High Court's decision, calling it "a real step in acknowledging gay rights," as well as "a step toward Israel joining the modern world."
Fellow Meretz MK Ran Cohen also called the decision "a huge stride forward for civil rights in Israel."