Jerusalem (CNN) -- Tzipi Livni, Israel's former foreign minister, lost her fight to remain head of Kadima, Israel's main opposition party.
She was defeated in a party leadership preliminary after midnight Tuesday, losing to her party deputy and former Israel Defense Forces chief Shaul Mofaz, who took 62% of the votes to Livni's 38%.
Livni, 53, gained international prominence in 2009 as foreign minister under Prime Minister Ehud Olmert.
She and Defense Minister Ehud Barak spearheaded Operation Cast Lead, Israel's extensive military offense in Gaza. She also played a major role in helping end Israel's 2006 war with Hezbollah in Lebanon.
After the vote, Mofaz, an outspoken critic of Livni's leadership, announced plans to lead his party to victory over current Israeli Prime Minister Benjamin Netanyahu, the head of Israel's ruling coalition.
"I intend to lead Israel towards a new social order. It is a battle for the image, the character and future of our country," Mofaz said. Kadima holds 28 of the 120 seats in the Israeli parliament.
The Iranian-born Mofaz, 63, is Kadima's fourth leader since its establishment by Ariel Sharon in 2005. Mofaz served as defense minister under Sharon.
Sharon defected from the right-of-center Likud faction over political differences to create a new centrist party, pulling key members both from Likud and the leftist Labor party.
Olmert took over for Sharon when he fell into a coma in 2006 and was later forced to step down from his role as prime minister due to allegations of corruption.
"I have called Mofaz and wished him luck," Livni told reporters early Wednesday. "These have been a very long couple of months. I want to thank my supporters and now I am going to get some sleep."
Livni refused to answer any questions regarding her political future. There has been speculation in the Israeli media that she may leave politics or start a new party.
Mofaz asked Livni to remain in Kadima.
"Tzipi, your place is with us," he said.
Speaking to Army Radio Wednesday, Dalia Itzik, a Kadima parliament member, dismissed the retirement rumors.
"I just can't see her going home. She is still a young woman and has many rounds ahead of her," she said.