UNITED NATIONS — One of the leading candidates to become Israel’s next premier, Foreign Minister Tzipi Livni, says she intends to maintain the current drive to reach political agreements with Palestinian Arabs and act on other “national interests” even before leadership changes in Jerusalem.

Ms. Livni’s rivals, especially among her former colleagues at the Likud Party, raise the concern that the current government may saddle its successor with irreversible concessions on the eve of a possible major political reshuffle. After Prime Minister Olmert’s announcement Wednesday of his intention to step aside by September, his government has no mandate to make major concessions, Likud members argue, adding Ms. Livni made a similar point back in 2000, when she was still a member of their party.

The current Likud leader, Benjamin Netanyahu, is heavily favored in national polls to win a national election, but he has no power to force such election. The current top party, Kadima, is expected to elect a leader to succeed Mr. Olmert in early September. Ms. Livni is competing for the spot against the transportation minister, Shaul Mofaz, a former Israel Defense Force chief of staff who is seen as more hawkish than Ms. Livni.

Speaking to reporters here yesterday after meeting Secretary-General Ban, Ms. Livni called on all Israeli political factions to join a government under Kadima’s leadership. But analysts yesterday expressed doubts that Kadima can maintain a governing coalition. If it fails to gather enough votes to support its government in the 120-member Knesset, a new election will likely be held by March 2009.

“The internal situation in Israel doesn’t affect the interests of Israel as a state,” Ms. Livni told reporters after meeting Secretary-General Ban here. Israel has participated in the Annapolis process, which has envisioned, prior to the end of President Bush’s tenure, the signing of a treaty detailing the creation of a Palestinian Arab state, she noted. “We promised to make all the effort to do so this year, and we’ll continue to do so,” she said.

Ms. Livni said that traditional political divisions in Israel are “a thing of the past,” adding that most parties share an agenda on the diplomatic front and over security goals, calling on “every party that can be a partner on such an agenda to join the government” under a new Kadima leadership.

But Likud spokesmen, who have already rejected a call by Mr. Mofaz to join a Kadima-led national unity government, were seething yesterday. “This is chutzpa,” a leading Knesset hawk, Yuval Steinitz of Likud, told The New York Sun. “There are certain norms. When an election approaches, you make no significant moves that shackle the next administration.”

In 2000, Ehud Barak, who was then prime minister and is now defense minister, conducted last-minute negotiations in Taba, Egypt, with the Palestinian Authority president at the time, Yasser Arafat, just prior to the end of President Clinton’s administration, and on an eve of an Israeli election. “When Barak conducted the Taba talks, Livni protested, saying he had no mandate to do so,” Mr. Steinitz said. “Now she does exactly the same.”

In an opinion poll conducted by Israel’s Channel 10 News on Wednesday, 36% of potential voters said they preferred Mr. Netanyahu to lead the next government, while 24.6% said they would support Ms. Livni, if she led Kadima. 11.9% favored the Labor Party’s leader, Mr. Barak. If Mr. Mofaz leads Kadima, Mr. Natanyahu’s support numbers rise to 26.6% against Messrs. Barak with 14.8% and Mofaz with 12.4%.

Mr. Mofaz is more likely than Ms. Livni, however, to keep the current governing coalition intact, as an Orthodox party, Shas, is likely to drop out if Ms. Livni leads Kadima, forcing a new election.