The official count of Mexico's presidential election has confirmed Enrique Pena Nieto's victory, paving the way for his Institutional Revolutionary Party (PRI), in opposition for 12 years, to assume power, the electoral authority has said.
The announcement on Friday seals Pena Nieto's victory and is a major step toward the resolution of the contested vote.
Pena Nieto secured 38 per cent of the vote while his main challenger, Andres Manuel Lopez Obrador, polled more than 31 per cent. Pena Nieto had an advantage of more than 3.3 million votes.
Just over 99 per cent of the ballot boxes had been counted as of 9pm on Thursday. More than half of the boxes were double-checked due to the possibility of fraud.
Lopez Obrador alleges Pena Nieto's party bought votes although he has not specified exactly how many votes he believes were bought.
Josefina Vazquez Mota, the candidate for the National Action Party, which has been in office, also said earlier in the day that campaign spending violations had marred the vote in which she came in third.
The accusations are expected to become the basis of legal challenges to the final vote count, which must be certified in September by Mexico's Federal Electoral Tribunal.
'Review of campaign'
The tribunal has declined to overturn previously contested elections, including a 2006 presidential vote that was far closer
"We need electoral authorities to conduct a detailed review of campaign spending that obviously exceeded legal limits, and that was also associated with vote buying," Vazquez Mota said.
"In this election there were clear circumstances of inequity that had a decisive effect on the vote results."
She said that while the complaints would not invalidate the results, they should lead to changes in electoral laws to prevent such practices in the future.
The accusations began surfacing in June, but grew earlier this week as thousands of people rushed to grocery stores on the outskirts of Mexico City on Tuesday to redeem pre-paid gift cards worth about $7.50.
Many said they had been given to them by supporters of the PRI, prior to Sunday's elections. Under Mexican electoral law, giving such gifts is not illegal as long as the expense is reported to electoral authorities.
But giving gifts seeking to influence votes is a crime, though it is not generally viewed as grounds for overturning an election.
Eduardo Sanchez, PRI's spokesman, said on Thursday that the gift-card scheme had been "a theatrical representation" mounted by the left.
Sanchez claimed supporters of Lopez Obrador had taken hundreds of people to the stores, dressed them in PRI T-shirts, given them gift cards and brought TV cameras in to create the false impression that the PRI had given out the cards.
"They mounted a clumsy farce, a theatrical representation in which they dressed people in PRI T-shirts," Sanchez said.