Avigdor Lieberman, whose nationalist Yisrael Beitenu is a key member of Israel's ruling coalition, on Wednesday said he had no intention of leaving government a day after the Kadima party withdrew.
Despite differences with Israeli Prime Minister Benjamin Netanyahu over plans to expand the military conscription law to include more ultra-Orthodox Jews, Lieberman, who is also Foreign Minister, said he had no intention of quitting the coalition.
"We won't leave the coalition, we are going to continue to fight from within the government," he told Israel's army radio.
The centre-right Kadima party pulled out of Netanyahu's ruling coalition on Tuesday following a dispute over proposals to change the universal draft law.
The departure of the 28-seat party, the largest faction in parliament, reduced Netanyahu's overwhelming majority of 94 to 66 MPs within the 120-seat Knesset, or parliament.
But his largely rightwing coalition depends on the support of Yisrael Beitenu and its 15 seats.
Lieberman also said his party would on Wednesday present a draft bill on universal conscription to parliament which would compel all Israelis, including the ultra-Orthodox and members of Israel's Arab minority, to either serve in the army or perform some alternative form of national service.
The proposal is unlikely to find any backing from Netanyahu or members of his Likud party who want a much more gradual approach to expanding the draft law.
Although Lieberman admitted that the bill had little chance of winning a
majority, he said that Netanyahu would eventually be forced to come round to his position under pressure from public opinion ahead of elections which are due in October 2013.
On Tuesday, Shaul Mofaz pulled his Kadima faction out of the coalition just 70 days after joining it in a surprise move which had staved off an early September election.
Mofaz, who will lose his position as vice prime minister, said he was pulling out over Netanyahu's refusal to accept the conclusions of a committee headed by Kadima MP Yohanan Plessner.

Environment Minister Gilad Erdan, who is close to Netanyahu, ruled out an early election following Kadima's departure, telling the radio: "There won't be elections tomorrow.
"For more than three years, we managed without Kadima, and we intend to carry on," he told the radio.
Army radio said it was possible that elections could be pulled forward by six months to April but not due to the departure of Kadima or the dispute over universal conscription.
An early election could be called in a bid to avoid a voter backlash over the looming fiscal austerity measures that are likely to be imposed next year due to the economic slowdown, the radio 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 so-called Tal Law, which is due to expire on August 1.