Any change to the timetable for the first Palestinian elections in 15 years would deal a heavy blow to efforts to reconcile the rival administrations in Gaza and the West Bank, a top Hamas official warned.
Palestinian president Mahmud Abbas finally set the election dates in January, days before US counterpart Joe Biden took office promising to give negotiations more weight in the search for a solution to the Middle East conflict.
The polls are seen as a vital first step towards forging a united Palestinian voice in any future US-backed peace talks with Israel.
Abbas called a parliamentary election across the Palestinian territories for May 22, to be followed by a presidential election on July 31, saying that it was the fruit of a reconciliation deal struck with Hamas last September after a decade of false starts.
But with his once-dominant Fatah movement under challenge from breakaway factions as well as Gaza's ruling Islamists, there has been mounting speculation the 86-year-old president may yet again postpone the twin polls originally scheduled for 2010.
The head of the Hamas list for next month's vote, Khalil al-Hayya, said any postponement, however small, would undermine efforts to restore unity.
"A postponement would push the Palestinian people into the unknown, and I warn that this will complicate the situation, perpetuate and reinforce the division," Hayya said in an AFP interview.
"This would cause great frustration among the population and young people, and could lead to serious reactions," said Hayya, the second most powerful Hamas leader in Gaza after political chief Yahya Sinwar.
- 'National consensus' -
Opinion polls suggest there is unlikely to be a repetition of the upset landslide Hamas won over Fatah in the last parliamentary election in 2006, pushing the Palestinians to the brink of civil war the following year.
Abbas's party is expected to win the largest number of the 132 seats in parliament, although well short of a majority.
A large majority of voters -- 79 percent according to a poll published by the Jerusalem Media and Communication Centre this week -- consider the elections important.
Hayya said Hamas does not seek to lead the next Palestinian government, but rather to participate in a unity administration.
"We want a government of national consensus," he said.
"If it carries a reasonable and acceptable political programme, it can be a real opportunity to end the division, unify the institutions (and) end the (Israeli) blockade and Palestinian suffering.”
Hayya said that while he would love to see Hamas retain the 40 percent of the vote it won in 2006, he was realistic about the electoral costs of being a ruling party.
"Part of the Gaza Strip population was disappointed" by Hamas rule, which has seen three wars with Israel and no end in sight to its crippling blockade, he acknowledged.
- Jerusalem hurdle -
If Abbas decides postponement is the only way to avoid defeat in the presidential election set for July, there are a number of pretexts he can cite.
Top of the list is the voting rights of Palestinian residents of Israeli-annexed east Jerusalem.
Abbas has already indicated he could cancel or delay the elections if their rights are not respected.
Israel captured the city's Arab eastern sector along with the rest of the West Bank in the Six-Day War of 1967 and has since proclaimed it an integral part of its "eternal indivisible capital".
Veteran Prime Minister Benjamin Netanyahu, a right-winger who needs to reburnish his credentials after an inconclusive March 23 election in Israel, is bitterly opposed to any arrangement for east Jerusalem voting that might advance Palestinian claims in the city.
His government has strictly curtailed Palestinian political activity in the city in the run-up to polling day, arresting candidates and raiding political meetings.
On Monday, the electoral commission said most Palestinian voters in east Jerusalem will be able to vote in the city's West Bank suburbs.
However, the commission said it is still waiting for Israel to respond to its request to allow 6,300 Palestinians to vote in post offices in east Jerusalem, an arrangement enshrined in the Oslo peace accords of the 1990s and followed in previous elections.
Hayya said Hamas strongly opposed the measures taken by Israel in east Jerusalem and appealed for US and European support for free and fair elections.
"We warn against the obstruction of the elections by the occupation forces," he said.
"This could lead some people toward other options such as extremism, violence and terrorism."