Senior Likud members leaving the party and joining Prime Minister Ariel Sharon's Kadima party has become a regular occurrence over the past several weeks.
Last week Tzachi Hanegbi defected to Kadima and on Sunday morning, Defense Minister Shaul Mofaz announced his decision to quit the Likud for Sharon's new party.
Agriculture Minister and Likud leadership candidate Yisrael Katz said following Mofaz's dramatic announcement that “This is not just a blow for Likud, but for the credibility of all the country’s politicians."
"A person who says he is staying in Likud one day and then defects from the party the next day because of one poll is inflicting a major blow to politicians’ credibility," he said.
"I am certain Likud will recover. I am staying in the race (for party leadership) to unify the ranks and present Likud with a true and worthy leadership," he added.
Knesset member Ayoob Kara (Likud) said in response that "Mofaz continues to fail at the moment of truth and is abandoning his friends at the Likud, just like he abandoned his soldiers at Joseph's Tomb."
"Now the mask has been removed from Mofaz's face and he has been uncovered as another small politician who prefers his own benefit over the Likud. But the public is not stupid and the Likud will get stronger," Kara said.
Associates close to Benjamin Netanyahu said Mofaz's decision provides a new meaning to the "concept of opportunism."
"His move indicates his lack of values and inconsistency. The Likud is loyal to its values and will persist for many years, while Kadima, with all its hitchhikers, will dissipate and be forgotten," one aide said.
'Mofaz sold his ideology for a dubious seat'
'Defense minister's behavior embarrassing'
Meanwhile, Foreign Minister and candidate for Likud party leadership Silvan Shalom said he was surprised to hear of Mofaz's decision.
"Shaul Mofaz's drop in the polls led him to this situation," he said. “I was one of the first on Sharon's shopping list, but I said that I would not leave the Likud."
"I'm staying in my party and want to be the head of this movement," Shalom added.
Meretz faction leader MK Zahava Gal-On also responded to Mofaz's sudden announcement.
"Kadima has become a refugee camp for losers from different political parties, after they understand that they will not be elected in their own party," she said.
Labor Party Chairman Amir Peretz said in response that "Sharon is humiliating Israeli politics by buying every politician offering himself for sale in a bargain market without any ideology."
"Sharon's random collection of opportunists cannot provide an answer to the social problems or to the political issue," Peretz added.
Fellow Labor MK Danny Yatom also responded to Mofaz's decision, saying that the defense minister "sold his ideology for a dubious seat in Kadima."
"The defense minister's behavior is embarrassing and reveals the true face of someone who claimed to be ideological, especially after his wild criticism of the prime minister over the past week," he said.
Attila Somfalvi, Ronny Sofer and Ilan Marciano contributed to the report