A top leader of Israel's Labor Party threatened Monday to pull out of the government if there is no progress in peace talks, reflecting growing impatience with the stalemate in negotiations with the Palestinians.

An exit by Labor, a moderate party sitting uncomfortably alongside hawks in the ruling coalition, could undermine Prime Minister Benjamin Netanyahu's parliamentary majority and force an election. That would sideline Mideast peace efforts for months.

The pullout threat came from Labor Party stalwart Binyamin Ben-Eliezer.

"If I see real movement ... in the next month and a half or two months, an entry into negotiations, talks, sitting down, in teams, talking about the core issues ... then the Labor Party will continue to offer support," Ben-Eliezer told Army Radio. "If not, we will be out."

Labor's leader, Defense Minister Ehud Barak, has so far fended off demands to leave the government.

On Monday, he bent in the direction of Ben-Eliezer's ultimatum, pledging a party vote within three months about its future in the government. He told party lawmakers the peace process is central to Labor's participation in the coalition, and "it will obligate decisions in due course."

Barak has been the moderate face of Netanyahu's government, taking a prominent role in dealing with the Obama administration in its efforts to restart peace talks.

As prime minister in 2000, Barak offered the Palestinians a state in all of Gaza, more than 90 percent of the West Bank and parts of Jerusalem. Netanyahu has never adopted any of those positions.

The latest round of talks was launched in early September, but broke down just three weeks later in a dispute over Israeli settlements. The Palestinians say there can be no talks if Israel continues to build homes for Jews in settlements in the West Bank and east Jerusalem — captured lands claimed by the Palestinians.

This week, Netanyahu offered nonstop negotiations with Palestinian President Mahmoud Abbas until peace is reached.

In response, Abbas and his chief negotiator repeated Palestinian demands — a halt to Israeli settlement construction and a pledge that a future border give Palestinians all of the West Bank, Gaza and east Jerusalem, with minor exchanges of territory.

With talks stalled, the Palestinians have launched an international campaign seeking unilateral recognition of their state, even without a peace deal.

Netanyahu rejects any prior conditions for talks. On Monday, he told parliament's Foreign Affairs and Defense Committee that if the Palestinians continue to pursue their unilateral strategy instead of peace talks, Israel, too, can take unilateral steps.

"Every action will have a reaction. We hope it won't come to that, but we have different options," he was quoted as saying by a participant in the closed meeting.

Ben-Eliezer does not speak for all of his party, but several prominent members, including Cabinet ministers, have been on the point of revolt for months, charging that Netanyahu is not serious about peacemaking.

Labor has withered to a shadow of the juggernaut that held some 50 seats in the 120-seat parliament from 1948 to 1977 and ran the country with junior coalition partners.

Now Labor is just the fourth-largest party in the house, and polls show its slide continues. Even if Netanyahu loses Labor's 13 seats, his parliamentary majority would remain intact, though barely.

Counting Netanyahu's own Likud Party, the five hawkish parties in his coalition have 61 seats in the 120-seat parliament, a tiny majority even if Labor leaves.

Nonetheless, Labor has played a valuable role for Netanyahu, giving a coalition dominated by ideological hard-liners a boost of legitimacy with the international community.

Labor's threat to quit demonstrated how hard it is for any Israeli leader to put together a cohesive, long-lasting coalition government from a badly fragmented parliament with 12 parties.

That, in turn, underlined Israel's difficulty in making clear-cut decisions on vital issues.

The main opposition party is Kadima, founded by then-Prime Minister Ariel Sharon in late 2005. Even three years after the popular Sharon was felled by a stroke, Kadima won 28 seats in the 2009 election, more than twice as many as Labor.

Some Labor leaders fear if they leave the government and become buried in the parliamentary opposition, their party might all but disappear in the next election.