The Kadima party head threatened to quit Israeli Prime Minister Benjamin Netanyahu's ruling coalition on Wednesday over the issue of ultra-Orthodox Jewish military conscription.
Shaul Mofaz's threat came as the head of a panel charged with finding ways to conscript thousands of non-serving Orthodox Jews presented his recommendations, despite a decision by Netanyahu to dissolve the commission on July 2.
Committee head Yohanan Plesner, a member of Kadima, announced his recommendations at a press conference, urging the government to conscript all military age Israelis -- or make them carry out civilian service.
At a press conference afterwards, Mofaz who only joined the coalition two months ago publicly urged Netanyahu to implement the recommendations.
"The prime minister must approve the recommendations of the Plesner commission. That's our condition for staying in the governing coalition," he said.
"He must show evidence of leadership. He must create a new social reality in Israel: that's what we joined the government for."
The issue of military service of ultra-Orthodox Jews has proved thorny for Netanyahu, who presides over a coalition government of secular parties, which want to all Israelis to serve, and Orthodox parties.
Earlier this year, Netanyahu said he would bring forward elections in a move interpreted in part as a way to strengthen his government before a bid to replace the so-called Tal Law.
The law allowing ultra-Orthodox Jews to indefinitely postpone their military service was struck down by Israel's High Court in February.
But instead of proceeding with the early vote, Netanyahu brought the Kadima party led by Mofaz into his coalition, massively enlarging his government.
Mofaz said he was joining the government in a bid to find a good replacement to the Tal law and reacted angrily to Netanyahu's decision this week to dissolve the Plesner commission.
At a press conference on Wednesday, Plesner said he was recommending "all Orthodox Jews older than 18 years undertake obligatory military or civil service, with some able to pursue their studies and postpone their conscription until the age of 22."
He called for "the application of the principle of personal responsibility to those who seek to escape their obligations, which would mean imposing penalties," including removing tax breaks and government benefits from offenders.
"Arrangements should also be made so that tens of thousands of citizens, including the youth of the Arab community, can share their part of the burden by doing civil service," he said.
Military service is compulsory for Israelis over the age of 18, with men serving three years and women two. Arab-Israelis are exempted and a large number of ultra-Orthodox men have also avoided military service under the Tal law, due to expire in August.