Tegucigalpa, Honduras ? Honduras’ presidential election remained too close to call Wednesday, with the opposition candidate who was proclaimed victor three days ago leading by less than half a percentage point.

With nearly half the votes in Sunday’s election counted, Manuel Zelaya, of the opposition Liberal Party, had 48 percent, compared with 47.6 percent for Porfirio Lobo Sosa, of the ruling National Party, according to the Supreme Electoral Tribunal.

It was not clear why it took so long for the results to be released. Explanations have included computer problems, a last-minute change in quick-count procedures and accusations of wrongdoing from both major parties.

Aristides Mejia, the electoral tribunal’s president, declared Monday that the 52-year-old Zelaya won the election. His statement, based on a sample of just more than 1 percent of precincts, outraged Lobo Sosa’s camp, which noted that Mejia was the Liberal Party appointee to the tribunal, which is made up of party delegates.

Exit polls also showed Zelaya with a lead over Lobo Sosa, who was nominated by the party of President Ricardo Maduro. Zelaya declared victory, but Lobo Sosa has refused to concede.