Israeli Prime Minister Benjamin Netanyahu claimed victory Wednesday after a bitter election and last-minute declarations to boost his party's low opinion poll numbers.

With 99% of the votes counted, his Likud party grabbed at least 29 of the 120 seats in Knesset, according to unofficial numbers from the Israeli election committee.

Its main rival, the Zionist Union, got at least 24 seats, the committee said.

Netanyahu's road to victory was bumpy, with the final results a far cry from experts' predictions.

For weeks, his party was lagging in various opinion polls, prompting Netanyahu to make sharp turns toward the right during the final days of the campaign.

Days before the election, he said there would be no Palestinian state under him, reversing his earlier stance.

He also slammed Israeli Arabs for voting in large numbers, urging his supporters to head to the polls. Arabs make up about 20% of Israel's population.

Netanyahu's turnaround appeared to have boosted his Likud base and attracted voters from right-wing parties.

Some polls had put his party in second place behind the Zionist Union, while others predicted the two would be tied neck-and-neck.

\"He seems to have energized that right-wing base ... even inching a little bit ahead of him,\" CNN's Elise Labott said.

Wrong sampling method?

Pollster Avi Degani, who predicted a Likud victory all along, said other pollsters relied too heavily on Internet technology.

\"More of the sampling needed to be done by telephone,\" he said.

\"The Internet does not represent the state of Israel and the people of Israel,\" Degani said, referring to modern statistical methods.

\"It represents panels, and the panels are biased strongly to the center.\"

As Netanyahu's win reverberates, the main question remains: Did he gain extra seats because of an 11th-hour surge, or were the major polls skewed from the beginning?

What's next?

Shortly after opposition leader Isaac Herzog conceded and congratulated Netanyahu, the shift turned to the formation of a coalition government.

Israel's ballots are for political parties rather than individual candidates. No party has ever won a majority, but the victory goes to the party leader most suited to put together a 61-seat majority with coalition parties.

While a new government must be negotiated through the president's office, the results increase Netanyahu's ability to form a majority coalition out of the 120 seats.

An optimistic Netanyahu claimed victory shortly after polls closed and said he plans to work \"quickly and responsibly\" to form a new government.

\"Against all odds, we achieved this huge victory,\" he told cheering supporters. \"Now we should form a strong and stable government that will be able to take care of the security, safety and welfare of each and every citizen of Israel.\"

Official results will not be released until next week, with the process of building coalitions expected to take much longer.

\"Our country's everyday reality doesn't give us the luxury for delay,\" he said.

Last-minute shifts

After Netanyahu declared victory, Palestinian faction Hamas accused all Israeli parties of denying rights to its people.

\"Hamas doesn't see any difference between the Israeli parties because they all share the denial of our people's rights and keeps assaulting them (people),\" said Sami Abu Zuhri, a spokesman for Hamas.

\"We assure that the Palestinian resistance is strong and can impose the facts.\"

President Reuven Rivlin said a ruling government will be set up as soon as possible.

Consultations could start as soon as Sunday, his office said in a statement.

CNN's Oren Liebermann reported from Jerusalem, and Faith Karimi wrote and reported from Atlanta. CNN's Larry Register, Dana Ford and Kevin Flower contributed to this report.

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