By Gabriel Stargardter and Gustavo Palencia
TEGUCIGALPA (Reuters) - Honduras grappled with a slow-motion political crisis on Wednesday, with its president, a crime-fighting U.S. ally, edging ahead of his rival, a TV star whose supporters protested as his early lead in the weekend election evaporated.
Three days after polling stations closed in Honduras' presidential election, there was growing international concern and still a fifth of ballots left to count with no clear victor.
With around 82.89 percent of ballots counted, center-right President Juan Orlando Hernandez had 42.2 percent of the vote and challenger Salvador Nasralla was on 42.1 percent, the election tribunal said, with the president 3,000 votes in the lead.
Hernandez's blue-clad supporters celebrated, chanting the president's name at a base of his National Party in capital Tegucigalpa, TV images showed.
The flamboyant Nasralla, 64, who heads a coalition made up of leftist and centrist parties, had initially taken a strong lead against the center-right Hernandez.
But after issuing the first batch of results on Monday, the election tribunal went silent for about 36 hours, which it said was because results had been slow to arrive. It began issuing a fresh count sporadically from Tuesday afternoon.
Immediately, Hernandez began closing the gap, prompting Nasralla to say his victory was being stolen, and urge his supporters to take to the streets in protest.
"We've already won the election," Nasralla said in an angry television interview late on Tuesday. "I'm not going to tolerate this."
However, both candidates committed to respect the final result once every disputed vote had been scrutinized, issuing identical signed statements brokered by the Organization of American States on Wednesday afternoon.
International observers said the delays were damaging the credibility of authorities and threatened to undermine the legitimacy of the next president.
On Wednesday, a U.S. State Department spokeswoman urged Honduran authorities to review the election results without undue delay.
"It's critical that Honduran election authorities be able to work in a free and transparent manner without interference. We urge all candidates to respect the results," Heather Nauert said.
Pre-election opinion polls indicated that Hernandez had been favorite to win the vote in the poor Central American nation, which struggles with violence, drug gangs and corruption and has one of the world's highest murder rates.
Nasralla's supporters accused the electoral tribunal of only releasing results from regions that support Hernandez.
About 8,000 people heeded Nasralla's call on Wednesday, and marched through the capital, Tegucigalpa.
"I'm here so that justice and the will of the people is carried out, because we elected Salvador Nasralla, and Juan Orlando Hernandez wants to steal his victory," said 22-year-old David Ramirez, a red political flag draped over his shoulder.
Behind closed doors, the parties of Hernandez and Nasralla were discussing immunity from prosecution for current officials and carving up positions in government, two diplomats told Reuters on Tuesday.
As the vote count progressed at a glacial pace, Hernandez's National Party appears set to retain control of Congress.
With a booming, game-show host voice and finely coiffed hair, Nasralla is one of the country's best known faces, the host of programs that feature scantily clad women. In one interview, he boasted of his penis size and his sexual performance.
He is backed by leftist former President Manuel Zelaya, who was ousted in a coup in 2009 after he proposed a referendum on his re-election. The possible return of Zelaya risks fueling concern in Washington.
The United States has longstanding military ties to Honduras but few ideological allies among the current crop of Central American presidents.
Hernandez has won U.S. praise for helping tackle a flow of migrants to the north and extraditing drug cartel leaders to the United States. He was credited with lowering the murder rate and boosting the economy, but was also hurt by accusations of ties to illicit, drug-related financing that he denies.
A foreign diplomat in Tegucigalpa, who asked not to be named, said the U.S. would be concerned by a victory for the coalition led by "maverick" Nasralla.
But the diplomat added that a slim victory for Hernandez might be "the worst case scenario", as it would likely trigger protests and demands for a full vote count from an election tribunal with little credibility.
(Additional reporting by Dave Graham and Frank Jack Daniel; Editing by Steve Orlofsky and Rosalba O'Brien)