Mexico's presidential candidates wrap up their campaigns Wednesday night, four days ahead of national elections.

Opinion polls show conservative candidate Felipe Calderon and former Mexico City mayor Andres Manuel Lopez Obrador locked in a tight race ahead of former ruling party candidate Roberto Madrazo.

A member of the ruling National Action Party, Calderon is scheduled to hold his final rally in Guadalajara, the country's second-largest city. He has pledged to continue the economic policies of President Vicente Fox.

Lopez Obrador, who represents the liberal Democratic Revolution Party, will address supporters in Mexico City. The former mayor of the capital, Lopez Obrador has promised large public infrastructure projects as a way to create jobs, and hopes to fund the program by battling corruption and tax evasion.

Running third in the polls Madrazo is the candidate of the Institutional Revolutionary Party, or PRI, which governed Mexico from 1929 to 2000.

The candidate who wins Sunday's election will succeed Mr. Fox, who by law cannot seek a second term.

Some information for this report was provided by AFP, AP and Reuters.