PORT-AU-PRINCE, Haiti - Haitian President Rene Preval could see his economic projects and constitutional reform emerge as the big winners when long-delayed Senate elections are finally held on Sunday.

A Senate majority for his Lespwa party, which has a candidate running for every seat but one, would help Preval achieve a long sought-after reform of Haiti’s 1987 constitution, increasing executive powers and allowing presidents to seek consecutive five-year terms.

It would also build support for Preval’s economic programs, meant to relieve poverty in a nation where 80 percent of people live on less than $2 a day.

But Sunday’s vote could be more notable for who is not running.

Haiti’s provisional electoral council disqualified all candidates from former President Jean-Bertrand Aristide’s still-popular Fanmi Lavalas party - a fact that may cause unrest or tarnish election results.

Some in Port-au-Prince were worried about their safety on election day, which has long been associated with violence and intimidation in Haiti.

“Today is my last day on the street. I’m going home until Monday,” said Jean Rolin, a 35-year-old plumber who did not plan to vote.

A total of 79 candidates will vie for 12 Senate seats. With races involving five to 18 candidates each, most are expected to end in run-offs between the top two vote-getters. Preval’s party already holds six of 18 seats in the upper chamber.

Security forces including 9,000 U.N. peacekeepers are prepared for protests by Lavalas supporters and others who have threatened to disrupt voting because their candidates were banned from the ballot.

Both Aristide and his former party still enjoy widespread support, especially among Haiti’s urban poor.

Preval, who was prime minister under Aristide, was elected president in 2006 with strong Lavalas backing. But Aristide’s supporters now consider Preval a traitor for failing to return the exiled president to Haiti.

Lavalas petitioned the electoral council to allow its candidates to run for Senate, but its case was weakened by a split in the party. Council President Frantz-Gerard Verret said the candidates were disqualified because they failed to produce documents signed by Aristide, the party’s leader who was flown to exile in Africa on a U.S. plane during a 2004 rebellion.

“This is essentially a political decision,” University of Virginia Haiti expert Robert Fatton Jr. said, referring to the council’s ruling. “All the parties who made this decision are essentially united against Lavalas and want to marginalize Lavalas as far as they can.”

The electoral council, not the government, had a sole role in approving candidates, Preval said Thursday at a press conference with U.S. Secretary of State Hillary Clinton.

“We are doing everything in our power to ensure that the government is neutral in the running of the elections,” Preval said. He plans to return from the Summit of the Americas in Trinidad to vote in person on Sunday.

Clinton praised Haiti’s electoral process as free and fair, and called it a model to be emulated by nearby Cuba.

But the U.S. embassy in Port-au-Prince joined Canada and the Organization of American States in voicing concern when Lavalas was excluded from the ballot in February. U.N. Security Council delegates in March praised Lavalas for continuing to contest the decision.

Armed U.N. peacekeepers escorted ballots and voting materials to polling places in the capital on Saturday, and international election monitors fanned out to countryside precincts.

The elections were originally scheduled for late 2007, but canceled after the electoral council was dissolved amid infighting and an alleged assassination attempt on one of its members. Riots then toppled Haiti’s government and four successive hurricanes led to nearly 800 deaths last year.

Twelve seats are now vacant after 10 senators’ terms expired, one died in a car crash and another resigned.