Kadima chairwoman Tzipi Livni urged Prime Minister Benjamin Netanyahu on Monday to take steps to prevent negotiations with the Palestinians from collapsing.
"You must make the necessary decisions to continue peace talks, and Kadima will back every decision you make which will achieve this goal," the opposition leader told Netanyahu in a phone call.
Livni also said that she has lately refrained from publicly criticizing the government in order to allow negotiations with the Palestinian Authority to run smoothly, and assured that Kadima will continue this practice.
However she did stress that if the prime minister will make decisions that will lead peace talks astray, Kadima will harshly condemn them and will act accordingly.
"Kadima will stand against any move that could harm the future of the peace process," Livni said.
Israel resumed settlement construction on Monday after a 10-month building ban in the West Bank expired at midnight on Sunday.
Palestinian President Mahmoud Abbas has repeatedly vowed to walk out of talks, which began a month ago in Washington, if building resumes.
The United States, the European Union, and the United Nations all issued statements on Monday 'regretting' Israel's decision to resume settlement construction.