JERUSALEM -- Tzipi Livni, a former foreign minister who advocates territorial compromise with the Palestinians, announced her candidacy Tuesday in Israel's approaching elections, adding her name to an already-fractured array of centrist challengers to Prime Minister Benjamin Netanyahu.
Returning to politics after a hiatus of several months, Ms. Livni said she would lead a new party, the Movement, vowing to present an "ideological and personal alternative" to Mr. Netanyahu, whose Likud faction chose a heavily right-leaning slate in party primaries Monday.
Unlike other centrist candidates who have focused mostly on social and economic issues, Ms. Livni, the most prominent female politician in Israel in recent years, emphasized her political agenda at a news conference in which she announced that she would compete in the vote set for Jan. 22.
"I've come to fight for peace," she said. "And I will not lend a hand to those who are trying to turn peace into a dirty word."
A politician who was reared in the Likud, but later led the centrist Kadima party, Ms. Livni, 54, said she represents a view that "believes in the right to all of the land," but also in reaching an agreement with the Palestinians that would "keep Israel Jewish and democratic."
Citing indirect cease-fire talks between Israel and the Islamist group Hamas after the recent Israeli military offensive in the Gaza Strip, Ms. Livni accused Mr. Netanyahu of shunning negotiations with the more moderate Palestinian leadership in the West Bank.
"Everything is backwards: a government that negotiates with terror and freezes all dialogue with those who act to prevent attacks," she said, referring to Palestinian Authority President Mahmoud Abbas, with whom negotiations have broken down over continued Israeli settlement building on occupied land.
Accusing Mr. Netanyahu's government of rejecting the notion of a Palestinian state alongside Israel, Ms. Livni said it had ended up with "two Palestinian states -- one Palestinian state in the United Nations ... against our will, and the second a Hamas state in Gaza." She was referring to a vote expected Thursday at the U.N. General Assembly to upgrade the Palestinians' status there to that of a non-member observer state.
It was unclear how much traction Ms. Livni's message would have with voters now facing four competing centrist factions, each claiming the mantle of the main challenger to Mr. Netanyahu. The prime minister has joined with his ultra-nationalist foreign minister, Avigdor Lieberman, in a combined slate made up of their two parties.
Ms. Livni's centrist rivals promptly denounced her move as a selfish bid that would further divide the camp facing Mr. Netanyahu, who holds a commanding lead in public opinion polls.
Labor Party leader Shelly Yachimovich, who has urged other centrist challengers to unite behind her, called Ms. Livni's step "a serious mistake," asserting that a "big centrist force" was needed to defeat Mr. Netanyahu.
Ms. Livni argued that her candidacy would only draw more voters to the center, improving prospects for a large centrist bloc in parliament, while the Likud had become "an extremist party."
On Monday, Likud elected several leaders of its rightist flank to top positions in the party list, dropping more moderate figures, including two Cabinet ministers -- Dan Meridor and Benny Begin -- to lower slots.
Ms. Livni's return to politics came less than a year after she was unseated as the Kadima leader after a lackluster term at the helm of the opposition. Kadima had edged Likud by one parliamentary seat in the last national elections in 2009, but Ms. Livni was unable to form a governing coalition, consigning herself to the opposition benches, where she offered only a feeble challenge to Mr. Netanyahu's broad majority.
She had previously served as foreign minister in the government of former Prime Minister Ehud Olmert, acting as chief negotiator with the Palestinians.