Second presidential candidate challenges Mexican vote Vazquez Mota said that while the complaints wouldn't invalidate the election results, they should motivate changes in electoral laws to prevent such practices in the future. The accusations began surfacing during June, but sharpened early this week as thousands of people rushed to grocery stores on the outskirts of Mexico City Tuesday to redeem prepaid gift cards worth about 100 pesos ($7.50), which many said they had been given to them by supporters of the Institutional Revolutionary Party, or PRI, prior to Sunday's elections. Simply giving away such gifts is not illegal under Mexican electoral law, as long as the expense is reported to electoral authorities. But giving gifts seeking to influence votes is a crime, though is not generally viewed as grounds for overturning an election. PRI spokesman Eduardo Sanchez said Thursday that the gift-card scheme had been "a theatrical representation" mounted by the left. Sanchez claimed that supporters of Lopez Obrador had taken hundreds of people to the stores, dressed them in PRI T-shirts, given them gift cards, emptied store shelves to create an appearance of panic-buying, and brought TV cameras in to create the false impression the PRI had given them the cards. "They mounted a clumsy farce, a theatrical representation in which they dressed people in PRI T-shirts," Sanchez said. Earlier this week The Associated Press separately interviewed at least a dozen shoppers at one of the stores, all of whom said they had been given the cards by PRI supporters. There was no evidence of any Lopez Obrador supporters at the store. Cesar Yanez, the spokesman for Lopez Obrador's campaign, denied the PRI accusation. "That's absurd, I don't think even they believe that," said Yanez. They would do better to just accept their responsibility. Vazquez Mota also complained Thursday about pre-election polls that put Pena Nieto ahead by double digits; preliminary vote counts show his lead in votes at around six per cent. She said the erroneous polls "could only be interpreted as instruments of propaganda." Calculations of vote tally sheets and in some cases, a recount of ballots at some polling places, are currently being carried out by electoral authorities. With 97.34 per cent of that vote count completed, the margin of victory for Pena Nieto had not varied much from preliminary counts; by late Thursday, he was leading the race with 38.27 per cent, compared to 31.48 per cent for Lopez Obrador and 25.46 per cent for Vazquez Mota.