Tel Aviv  - New Israeli Prime Minister Benjamin Netanyahu may have achieved his aim of forming a broad-based unity coalition, but this does not guarantee him a premiership free of challenges.

Coalition requirements forced him to form a government with 30 ministers - so large that ministries had to be split to accommodate all the demands from various partners.

This, in turn, led to huge dissatisfaction inside his own right- wing Likud party, with senior legislators unhappy that the top cabinet posts were parceled out to coalition partners.

Although Netanyahu is regarded as a hawk by much of Israel and the world, his views are centrist compared to others in his party. These hardliners in his own faction, especially those who were not given government portfolios, can make his life difficult - as former Likud leader Ariel Sharon found after he defied many Likud legislators and went ahead with his unilateral pullout from the Gaza Strip.

But disgruntled Likud lawmakers aside, the weakest link in the coalition appears to be the party Netanyahu tried hardest to woo, the left-to-centre Labour Party.

Labour leader Ehud Barak was keen to join the coalition, but he faced strong opposition from legislators inside his party who feared their faction could become a "fig-leaf" to a right-wing coalition.

Barak succeeded in getting Netanyahu to commit to working toward a peace agreement with the Palestinians - a statement whose precise meaning, like beauty, is in the eye of the beholder.

Netanyahu is famously sceptical about the current negotiations with the Palestinians, saying all the while that it was better to first achieve a economic peace. Only as the February 10 election neared did he say that this would not be at the expense of diplomatic talks, but he has refused to publicly endorse a Palestinian state.

Should the peace talks proceed too slowly for Labour's liking, Barak will be under intense pressure to remove his party from the government.

But should the talks proceed apace, Netanyahu will face problems with right-wing coalition partners opposed to Israel making too many concessions. Deja vu for the premier, possibly, since it was the hardliners in his coalition who toppled his first government after he signed the Wye accords with the Palestinians in 1998.

The best Netanyahu can hope for is to find some middle ground, but occupying it will lead to problems internationally, since both the European Union and the Obama administration in Washington have made it clear they expect Israel to follow through on the peace process.

Netanyahu is also likely to face international pressure - as well trouble from the Labour Party - should Israel continue its settlement activities in the West Bank. But any slowdown is likely to raise the ire of his nationalist coalition partners, the Yisrael Beteinu party and the Jewish Home party.

It was precisely the expectations of the international pressure he would face with a narrow, right-wing government, which led Netanyahu to bring on board the Labour Party.

But in so doing he also brought on board sources of internal tensions.

Netanyahu's capitalism sits oddly with Labour's neo-socialism, and although a formula was found to satisfy both sides on the socio-economic divide, there is no guarantee it will last, especially if the current world economic slowdown intensifies, with a concomitant effect on the lower-income strata of Israeli society.

In the party-political sphere, things are no more stable. Barak angered many in his party when he decided to join the Netanyahu government.

Under party rules a new leadership contest must be held no later than 14 months after a party leader loses a general election, which means that by April 2010 Barak could find his leadership challenged.

Should an opponent to sitting in a government win the internal party leadership race, it is likely Labour will pull out the government - as happened in 2005, when newly-elected Labour leader Amir Peretz broke up a coalition partnership with the Likud, precipitating new elections.

"This is a large coalition with a lot of potential for tension," the Jerusalem Post daily quoted a Likud coalition negotiator as saying.

"We'll need to work hard and be flexible to keep it together, but think we can succeed." (dpa)