Israeli PM Ariel Sharon's new political party, Kadima, will strive to reach a final status agreement with the Palestinians, an ally says.
Mr Sharon's move has reconfigured Israel's political landscape
Meir Sheetrit said that if Kadima wins the March election, it will seek a permanent peace deal providing for "two states for two peoples".
Mr Sharon left the Likud party, which he helped establish in 1973, to found a new centrist party two weeks ago.
Meanwhile, Dalia Itzik will become the second Labour Party MP to join Kadima.
Ms Itzik, the former communications minister, is close to former Labour leader Shimon Peres and her departure has strengthened speculation that he may also defect.
Mr Peres, currently Israel's vice-premier, was ousted by Amir Peretz in a party leadership vote earlier this month.
"The decision is a tough one for me. It will take another day or two before I decide," Mr Peres said on Monday before leaving for the Euro-Med summit in Spain.
Mr Sheetrit, a minister without portfolio in Mr Sharon's government, said Kadima would try to reach a final status agreement in its first term in power.
"There is no alternative but to create two states for two peoples, a Palestinian state alongside the state of Israel, living in peace, which is, of course, the only condition," he told Israel Radio.
He also dismissed criticism from Likud that Kadima was a left-wing party.
"Many can join this consensus. We are not on the left side of the political map" he said.
Several opinion polls in Israeli newspapers have suggested that Kadima could win the election scheduled for 28 March.
Earlier on Tuesday, Ms Itzik praised Mr Sharon when she announced that she would leave the Labour Party and join Kadima.
"For years we have had no element to tip the balance between the two blocs. And suddenly this man, by his image and actions, succeeded in rising above those traditional voting patterns," she told Israeli army radio.
Ms Itzik criticised the new Labour leader for his "hostile takeover" from her ally Mr Peres and said Mr Peretz had adopted alarmingly left-wing diplomatic policy platform.
But she was unsure whether Mr Peres would join her.
"It could turn out that he will be in one place and I will be in another," she told Israeli army radio.