Israeli Prime Minister Benjamin Netanyahu's ruling Likud party has approved an electoral pact with the ultranationalist Yisrael Beitenu, overcoming internal opposition within Likud. Opponents of the temporary alliance for the January general election failed in their bid to have the matter decided by secret ballot and the motion passed by an overwhelming show of hands on Monday. "In the face of the security and financial challenges we need unity and responsibility," Netanyahu told members of the Likud's governing central committee convened in Tel Aviv to vote on his proposal for a partnership with the far-right party headed by Foreign minister Avigdor Lieberman. "At this time, it's essential that national camp unites forces. That's why I asked Lieberman to run with the Likud," he said. Netanyahu said his party would remain independent, and "continue our way in preserving our security, heritage, economy." Likud holds 27 of the 120 seats in the outgoing Knesset, or parliament, while Lieberman's Yisrael Beitenu has 15 seats. Polls predict that working as a team will give them at least as many members in the next parliament and probably more. Internal opposition to the plan was led by Public Services Minister Michael Eitan, who called it "a mistake that will undermine Likud" - but his bid to have it put to a secret ballot failed to garner enough support. As the party faithful were herded on Monday evening through tight security at a conference centre in northern Tel Aviv, Eitan and a number of aides were seen scrambling to obtain the necessary signatures. Even those strongly against the merger were hesitant about visibly defying Netanyahu, who looks set to be easily re-elected as premier in January. "I'm opposed to the deal with Lieberman, but don't want to embarrass Netanyahu by voting against him," a Likud official said, speaking on condition of anonymity. "With a heavy heart, I'll vote in favour." A poll published on Monday in the Maariv daily predicted the alliance would get 43 seats, with the opposition Labour party getting 20.