Aslıhan DOĞRU -TDO- The Mexican people are holding a referendum on Sunday.
The referendum, backed by President Andres Manuel Lopez Obrador, is about whether the country's five former heads of state should be investigated.
Lopez Obrador describes past administrations as corrupt.
For the results to be binding, at least 40% of registered Mexican voters, or about 37 million people, must go to the polls.
Lopez Obrador accuses Carlos Salinas, Ernesto Zedillo, Vicente Fox, Felipe Calderon and Enrique Peña Nieto, leaders of administrations ranging from 1988 to 2018, to worsen Mexico's situation in many areas, such as poverty and instability.