[JURIST] Mexico's Federal Electoral Institute [official website, in Spanish] is set for Wednesday's start of the official legal count of ballots cast in Sunday's disputed presidential election [BBC Q/A] after preliminary results [El Universal coverage] led to the two main candidates each declaring themselves the winner. Conservative candidate Felipe Calderon [campaign website, in Spanish; Wikipedia profile], of the National Action Party (PAN) [party website, in Spanish; Wikipedia backgrounder] said Monday that his 370,000-vote lead is insurmountable [AP report], but leftist candidate Andres Manuel Lopez Obrador [campaign website, in Spanish; Wikipedia profile] of the Democratic Revolution Party (PRD) [party website, in Spanish; Wikipedia backgrounder] has refused to concede the election, saying he has the right to challenge the results [Reuters report]. The latest preliminary results Monday afternoon indicate that Calderon has received 36.37 percent of the vote, with Lopez Obrador trailing at 35.37 percent. Lopez Obrador has alleged fraud in the elections and said that by his calculation he has won by 500,000 votes.

The preliminary numbers released by the Federal Electoral Institute are based on a sampling of votes, but the legal count to begin Wednesday will include all ballots and will be observed by all major political parties – PAN, PRD and the Institutional Revolutionary Party (PRI) [official website; Wikipedia backgrounder]. Local district councils will calculate returns based on reports attached to sealed ballot boxes. If the report is unclear or if the ballot box appears to have been tampered with, officials will recount the individual ballots. There is a Thursday deadline to allege irregularities at polling places and parties have until next week to lodge a complaint against the district counts. Any dispute would ultimately be heard by the Electoral Tribunal of the Federal Judiciary [official website], and analysts are predicting that the court will ultimately consider the disputed presidential election [AP report].

Several allegations of voting irregularities [AP report] have already popped up throughout the country, with the most prominent complaints stemming from Mexican citizens living in the US who crossed the border to vote in Sunday's elections. Last year, Mexico's Congress passed a law extending suffrage to expatriates and set up 86 special polling stations for them to vote on election day. Each special polling station, however, had only 750 ballots to prevent voter fraud, thus disenfranchising thousands that crossed the border to vote at the special polling stations. Though expatriates streamed into Mexico to vote and Mexican citizens abroad cast absentee ballots for the first time, their voting bloc is not expected to have an impact on the election, primarily because many Mexican citizens live abroad illegally and feared alerting US authorities to their status. The Washington Post has more.