Mexico City (CNN) -- The leader of Mexico's leftist Party of the Democratic Revolution, Andres Manuel Lopez Obrador, announced Tuesday that he has asked Mexico's Federal Election Institute for a recount of the ballots cast in Sunday's presidential election. 

Lopez Obrador's demand came the day after he said the vote had been "plagued by irregularities." 

Election authorities have projected Lopez Obrador as the runner-up in the vote. 

Mexico's presumed president-elect, Enrique Peña Nieto, said Monday it was time for his country to leave behind the political rancor of campaign season. 

Political tensions flare after Mexican presidential vote 

The Federal Election Institute, known by its Spanish acronym IFE, says it expects the final count results Sunday. That's when each of the approximately 143,000 polling stations are supposed to have finished counting votes and signed an "act" detailing the number of votes. 

Wednesday marks the beginning of the district count, in which each of the 300 electoral districts will scrutinize the acts. 

Ballots will be recounted in cases where: 

-- The difference between the first and second place candidate is 1% or less; 

-- The number of annulled votes is greater than the difference between the first and second place candidates. 

Ana Isabel Fuentes, international coordinator of information for IFE, said she expects the law to mandate recounts in 19 districts, representing about a third of the total ballots cast. 

Lopez Obrador must wait until Sunday to formally submit any application for a recount to the Federal Election Tribunal. Any candidate can challenge, but National Action Party candidate Josefina Vazquez Mota has already conceded. 
Who is Andres Manuel Lopez?
The leader of Mexico's leftist Party of the Democratic Revolution, Andres Manuel Lopez