Olmert and Kadima leaders fear the public outcry over the Winograd report could force Labor to quit the government even before its primaries at the end of the month. Moves at Labor to abandon Olmert are expanding.
Olmert's aides said Thursday that the coalition's test will be its ability to survive until June, when Labor's second round of primaries is due.
Labor secretary general Eitan Cabel, who resigned from the cabinet this week, said he would convene the party's central committee on May 13 to vote on quitting the government.

The central committee will be asked to vote on proposals ruling out a partnership in an Olmert-headed coalition, but not in a government headed by another Kadima member.
"There is no reason not to cooperate with another candidate from Kadima," said MK Ophir Pines-Paz, who initiated the central committee meeting. "We won't interfere with Kadima's decision as long as it offers a worthy alternative to Olmert."
Olmert, who managed to stymie the rebellion against him in his party, faces another test in the Knesset next Monday in a no-confidence vote because of the Winograd report.
Certain Labor MKs intend to stay away from the plenum or vote for the no-confidence motion.
Pines said he would not vote for the government. "I believe I won't be alone," he said.
MK Shelly Yachimovich is also determined not to support the government in the vote and is considering what course to take. On Thursday, Yachimovich called on Defense Minister Amir Peretz to resign and distinguish himself from what she called the disgraceful behavior of the prime minister. Peretz himself may join the initiative to abandon Olmert's government.
Cabel and MK Ami Ayalon are also deliberating.
MK Marina Solodkin (Kadima) said she too would not support the government.
Olmert's associates checked the power balance and concluded that 10 Labor MKs at the most might revolt against toeing the party line, claiming the vote was on a matter of principle.
In any case Olmert will have a large majority, his aides said.
Cabinet secretary Yisrael Maimon and Olmert's adviser Oved Yehezkel met MK Avraham Ravitz (United Torah Judaism) on Thursday to ask for UTJ's support from outside the coalition.
Olmert has still not decided what to do about Foreign Minister Tzipi Livni, who called on him to resign but did not quit herself. His aides believe that he does not wish to rock the boat at Kadima or the coalition after having stabilized them and will save Livni's dismissal as a future option.
Livni hinted Thursday that she had not said her last about remaining in the cabinet and may resign.
Labor's central committee poses yet another threat to Olmert's political survival. If the committee decides that Labor must quit, Olmert would be left even before Labor's leadership showdown without his senior coalition partner.
Even if the committee does not decide to quit, its very gathering will force former prime minister Ehud Barak to voice his view about the harsh conclusions of the interim report regarding Olmert.