Mexico’s President-elect, Enrique Peña Nieto, has directed police to build barricades around the San Lázaro Legislative Palace in advance of his December 1 inauguration there, in case of civil unrest.

In July, Peña Nieto, the candidate of the Partido Revolucionario Institucional, won the presidential election against his left-wing opponent, Andres Manuel Lopez Obrador, by 6.6 points, according to the official vote count. The announcement of Peña Nieto’s victory was immediately followed by a challenge to the election’s legitimacy. Lopez Obrador called the result “fraudulent,” accusing the PRI of buying at least 1 million votes and of exceeding the campaign finance limit. The PRI has a long history of corruption, repression and hegemonic one-party rule in Mexico.