Mexico's main leftist party on Tuesday demanded a ballot-by-ballot recount in the closest presidential election, claiming the vote was manipulated.

Lopez Obrador, the candidate for the leftist Party of the Democratic Revolution (PRD), has rejected provisional results that gave conservative Felipe Calderon, of the ruling National Action Party (PAN) a one-point lead in the July 2 election.

About 3 million ballots were not part of that count because of problems, electoral officials said Tuesday. Obrador, however, had claimed the votes had gone "missing."

The demand for a recount of all 41 million votes cast Sunday set up a possible showdown that could go to Mexico's electoral courts.

The issue of ballot recount raised fears of bitter and lengthy legal disputes similar to the electoral debacle in Florida that delayed the outcome of the 2000 US presidential election by five weeks.

Interior Secretary Carlos Abascal said that recounting every ballot was "physically impossible and also legally impossible."

On Wednesday, the Federal Electoral Institute was set to start verifying the tallies sent in from polling stations nationwide. Political party representatives may raise objections to specific tallies and request they be compared with the actual ballots.

(Xinhua News Agency July 5, 2006)