The Palestinians are preparing to conduct their first census in a decade, with hopes the results will help them in future peace talks with Israel.

Demographics play a central role in the Israeli-Palestinian conflict. Rapid Palestinian growth would bolster Palestinian territorial demands, while Israelis' fear of being outnumbered in areas they now control might make them more willing to consider a West Bank withdrawal.

Later this week, some 5,000 census-takers will fan out across the West Bank and the Gaza Strip, first to count buildings, and, in December, to count people. Results are expected by February.

"We hope we can use these statistics in the negotiations," said Palestinian negotiator Saeb Erekat, a supporter of moderate Palestinian President Mahmoud Abbas and his Ramallah-based administration. "It's not only important for the political process, but also for building the institutions of the state."

The militant group Hamas, which controls the Gaza Strip, has also said the census results are important and that it will cooperate.

The first Palestinian census, conducted in 1997, counted 2.89 million Palestinians in the West Bank, Gaza and east Jerusalem, the territories Israel captured in the 1967 Mideast War. According to estimates by the Palestinian Central Bureau of Statistics, the figure now stands at 3.9 million.

Some Israeli critics have dismissed the 1997 figures and the current projections as inflated, a charge denied by Palestinian census officials, who say the counts are being conducted under international scrutiny.

Palestinians have one of the highest birth rates in the world, forcing Israel to consider the possibility that Jews, despite ongoing Jewish immigration, will one day be a minority in historic Palestine, the area between the Jordan River and the Mediterranean.

In December 2006, Israel's population included 5.4 million Jews, 1.4 million Arabs and 310,000 others, according to Israeli government figures.

Demographic concerns are often cited by those in Israel who want to withdraw from some of the lands Israel occupied in the 1967 Mideast War. It also was a key factor in former Prime Minister Ariel Sharon's decision to withdraw from Gaza in 2005.

The census will cost $8.6 million, with the Palestinian Authority paying 20 percent. The rest comes from a U.N. agency, Saudi Arabia, the Swiss Agency for Development and Cooperation, the Netherlands and the Organization of Petroleum Exporting Countries, census officials said.

Hafedh Chkeir, an official with the U.N. Population Fund, said his agency trusts the work of the Palestinian census agency. He also said the U.N. is trying to bring in some Arab experts based in Jordan, but they have not yet received visas from Israel.

On Saturday, census-takers will start affixing numbers to homes, business and other buildings. In radio and TV ads, Palestinians are being urged to cooperate and not to remove the numbers.

Israeli-Palestinian peace talks have been frozen since a failed summit in 2000, but new momentum has been building. Negotiating teams from both sides are trying to draft a joint statement of principles that is to be presented to a U.S.-hosted peace conference later this fall, possibly the launching pad for new talks.

The first census was conducted at a relatively quiet time, with hopes still running high that the two sides were on their way to a final peace deal. However, since then, years of bloody fighting have reshaped the area.

The Palestinians now have two rival governments, one run by Hamas in Gaza and the other by Western-backed moderates in the West Bank.

During the last census, Israel did not permit a head count in the Arab neighborhoods of east Jerusalem, claimed by the Palestinians as a future capital, prompting census-takers to draw estimates for that area using 1995 Israeli figures. Israel said at the time that a Palestinian census there was a challenge to its sovereignty in the city.

It was not clear whether Israel would permit a census in east Jerusalem this year. Israeli officials did not return repeated messages seeking comment on the matter.