Mexico's presidential candidates have made their last bid for votes ahead of hotly-contested 2 July polls.
Felipe Calderon tells supporters he is the right man to lead Mexico
Candidates addressed crowds in their electoral strongholds before a ban on campaigning, giving voters time to reflect, took effect from Thursday.
Leftist Andres Manuel Lopez Obrador and conservative Felipe Calderon are seen as frontrunners in a very tight race.
The campaigns have been marked by bitterly-traded political insults and accompanied by a rise in drug violence.
Mr Lopez Obrador, a former mayor of Mexico City, addressed tens of thousands of supporters at a rally in the capital's central square, the Zocalo.
He said Sunday's election "will demonstrate that money doesn't always win out over the morality and dignity of the people".
Ecstatic support for Lopez Obrador in the city he once ran
He also tried to allay fears that the economy would suffer under his leadership.
"The economy will be handled with technical policies, not ideology," he said.
His main rival, Mr Calderon, a candidate of President Vicente Fox's National Action Party (PAN), staged his final campaign rally in Mexico's second biggest city, Guadalajara.
He told his supporters he was the right man to lead Mexico into the future.
"One project, the PAN's, guarantees economic stability, the other doesn't," Mr Calderon said.
Roberto Madrazo, the candidate of the Institutional Revolutionary party (PRI), which ran Mexico for 71 years and is still the country's biggest political party, ended his campaign in the state of Veracruz.
Roberto Madrazo is the candidate for the still powerful PRI
He has been trying to convince voters that it is not a two-horse race.
"Our party is a winner. Our party was born to win, born to prevail," Mr Madrazo told supporters.
The other candidates are Patricia Mercado who is standing for the Social Democrat and Peasant Alternative Party and Roberto Campa, the candidate of the New Alliance.
Whoever wins faces the challenge of generating growth and creating jobs, moves that would help stem the flow of migrants to the US.
Tackling drug trafficking and brutal violence surrounding it is another issue the new president will have to face.
The last week of campaigning coincided with a surge in drug-related killings.
About a dozen people were murdered in the state of Guerrero on the Pacific coast at the weekend, including four police officers.
Another policeman was killed on Monday night in the resort of Cancun.
The Mexican government has said the killings will not disrupt voting in Sunday's election.
Elections for Congress are also being held on Sunday. It is unlikely that one party will get a majority, so the new president is set to face the same legislative stalemates as the current president, Vicente Fox, has done during his six-year term.
Mexican electoral law requires all campaigning to stop after midnight on Wednesday to give voters some time for reflection before the vote on Sunday.
"The spirit of this law is to give people some peace to discuss the issues for themselves, free of interference," Rolando de Lasse of the Federal Electoral Institute told the Associated Press news agency.