Mexican President-elect Enrique Pena Nieto no longer has any legal obstructions barring his path to power after the country's highest electoral court dismissed an appeal from leftist opposition candidate Andres Manuel Lopez Obrador challenging the election results.

Lopez Obrador, who lost to Pena Nieto by over a six-point margin in July, accused the Institutional Revolutionary Party (PRI) candidate of buying votes, overspending on campaigning and using connections to gain favorable media coverage.

The seven judges on the Federal Electoral Tribunal unanimously rejected the appeal Thursday, saying there was insufficient evidence of wrongdoing.

"There is no proof of vote-buying, there is no proof of coercion," Justice Flavio Galvan Rivera said of the ruling.

Roughly 200 demonstrators held protests outside the courthouse after the ruling, while Lopez Obrador's campaign manager Ricardo Monreal likened the tribunal to "a gang of ruffians."

One of the primary allegations against Pena Nieto was that his campaign had handed out over $5 million worth of pre-paid gift cards to voters for the grocery store chain Soriana before the election.

"Even though the existence of the Soriana cards is proven ... it has not been proven they were handed out, nor that they were in exchange for votes for Enrique Pena Nieto," Justice Pedro Penagos said.

Critics of the ruling have levied that the tribunal conducted no interviews with any of the gift card recipients in the course of its investigation.

Monreal complained that Lopez Obrador's legal team was expected "to supply not just the evidence, but (also) the victims and criminals."

Pena Nieto is expected to take office Dec.1, returning the PRI to power, which it had previously held for 71 years from 1929 to 2000, gaining a reputation for rampant corruption and abuses.

"It is time to begin a new phase of work on behalf of Mexico," Pena Nieto posted on his Twitter account after the ruling.

"With dialogue, understanding and agreements, we move forward together for the unity and greatness of Mexico."

Outside the courthouse Friday, the Associated Press reported that one of the demonstrators called for a "funeral march for democracy."