MEXICO CITY (Reuters) - Enrique Pena Nieto won Mexico's July 1 presidential election by 3.3 million ballots, or almost 7 percentage points, although allegations of excessive campaign spending and voter fraud could be reviewed by the electoral tribunal, officials said on Sunday.
Vote counts also confirmed that Pena Nieto's Institutional Revolutionary Party (PRI) and its allies in the Green Party would have a minority in both houses of Congress, which could complicate his agenda when he takes office in December.
According to the final count, Pena Nieto got 19.2 million votes, or 38.21 percent, compared to 15.9 million, or 31.59 percent, for leftist Andres Manuel Lopez Obrador.
In third place with 12.8 million votes, or 25.4 percent, was Josefina Vazquez Mota of the National Action Party, or PAN, of President Felipe Calderon, who was barred by the constitution from running for a second term. The PAN was hurt by a sluggish economy and dissatisfaction over drug-related violence.
Calderon has congratulated Pena Nieto on his election win, as have leaders from dozens of other countries.
Mexican tribunals have until September to rule on any wrongdoing and officially name Pena Nieto as president.
Calculations by electoral officials projected that the PRI and its Green Party allies will have 240 deputies in the 500-seat lower house of Congress, which will convene in September.
Pena Nieto, however, may also be able to garner support from 10 deputies from the centrist New Alliance party.
The PAN will have 116 deputies, according to the projections. But Calderon's party may also support energy and labour reforms that Pena Nieto has proposed. The president-elect has advocated allowing foreign investment into the oil industry and making it easier for employers to hire and fire workers.
Three leftist parties, who want to keep existing labour protections and national control of the oil industry, have the remaining 134 seats in the lower house.
In the 128-seat Senate, the PRI and Green Party will have 62 seats, followed by the PAN with 38. The three leftist parties will have 27 senators, according to the projections.
The number of deputies and senators could change following rulings by the electoral tribunal, officials said.
Both Lopez Obrador and the PAN have alleged that Pena Nieto overspent, although they have yet to file legal complaints to the tribunal.
Lopez Obrador said Saturday that he is gathering evidence for a legal challenge and urged the PAN to join him.
Tens of thousands also marched through the Mexican capital against Pena Nieto on Saturday, holding banners accusing him of being corrupt and authoritarian.
Pena Nieto denies wrongdoing and PRI officials say they could sue Lopez Obrador over his accusations.
Pena Nieto's win returns the PRI to presidential power after 12 years in the wilderness. It had previously held the presidency continually from 1929 until 2000. (Additional reporting by Ioan Grillo; Editing by Paul Simao)