JERUSALEM (CNN) -- Former Israeli Prime Minister Shimon Peres will resign from the Labor Party, Israeli Channel 10 reported Tuesday night.Peres' office would neither confirm nor deny the report. Peres was in Spain and not available for comment Tuesday.The Channel 10 report said that Peres will support the peace effort of Israeli Prime Minister Ariel Sharon but will not run for another term in the Knesset, Israel's parliament.Peres was recently defeated by Amir Peretz in elections for Labor Party chairman. Peres, 82, has been a pillar of the left-leaning party for decades.During that time, he and Sharon have been political rivals but remained friends.Last week, Sharon left the right-leaning Likud bloc -- which he helped found in the 1970s -- and announced the creation of a new party, Kadima, officially separating himself from those in Likud who protested his pullout of Israeli settlers and troops from Gaza.Sharon's move, which was widely expected, revolutionizes the Israeli political scene. Kadima, which means "forward," is expected to end the longtime dominance of two parties in Israeli politics, Likud and the Labor.At a news conference after his announcement, Sharon said he thought Peres was considering quitting politics after his Labor defeat, but he was lavish in his praise of Peres, whom he said he has known since the 1950s.Peres is in Barcelona, Spain, where a joint Israeli-Palestinian soccer "peace team" -- sponsored by the Shimon Peres Center for Peace -- was to play a match against FC Barcelona.Aides said that Peres will return to Israel on Wednesday afternoon. He is expected to talk then with reporters about his plans.In Barcelona on Tuesday, Peres also had kind words for Sharon but told The Associated Press he would "decide tomorrow night" about whether to leave Labor."The real change is not in the Labor Party. The real change is in the Likud Party," he told the AP. "Mr. Sharon took a different direction for a Palestinian state. He wants to continue the peace process."Kadima met Monday, and its leaders laid out central principles publicly for the first time, supporting the creation of a peaceful Palestinian state, giving up some land to ensure Israel's Jewish majority, and maintaining all of Jerusalem under Israeli control.The announcement brought few surprises. The points laid out have long been espoused by Sharon and his supporters."The people of Israel have a national and historic right to the land of Israel," Justice Minister Tzipi Livni said at the meeting. "Because there is a need for Israel to remain a Jewish majority, we will have to give up part of the land of Israel in order to maintain a democratic, Jewish state."She added that the party supports "the establishment of a Palestinian state alongside Israel.""The Palestinians will have to commit to dismantle the terror organizations, collect illegal arms and carry out security reforms," Livni said. "Israel will keep the major settlement blocks and Jerusalem will remain unified."She said political settlements will be based on the "road map" for Middle East peace backed by the United States, the European Union, Russia and the United Nations.The new party's principles overlap in several areas with those of Labor and Likud. But Kadima positions itself as a centrist alternative and has attracted prominent members of both camps.Livni vowed that Kadima "will work to alter the method of governance in Israel."Kadima officials cautioned that the party is in its infancy and that its platform may grow and change.Polls taken last week suggested that if the elections took place immediately, Kadima would win the most seats in the 120-member Knesset.The report of Peres' decision to back Sharon's new party comes days after nearly 1,600 people crossed the Gaza-Egypt line in both directions, passing through the first-ever Palestinian-controlled international border. (Full story)The deal that led to the historic opening of the Rafah Crossing was announced earlier this month by U.S. Secretary of State Condoleezza Rice.Copyright 2005 CNN. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed. Associated Press contributed to this report.