On May 4, 2012, Vice Mayor
Isko Moreno joined the
Pwersa ng Masang Pilipino party, fueling speculations that he would be former President
Joseph Estrada's running mate. Estrada would confirm this on May 9, 2012, but, for one term only. On May 7, 2012, Incumbent Mayor
Alfredo Lim announced he will run for re-election and said that Moreno was his original running mate. A year prior to the election, Estrada transferred his residence from
San Juan to
Santa Mesa, Manila; this was made official by the Manila City Hall. Estrada's Manila home was formerly the headquarters of President
Ramon Magsaysay during the
1953 presidential election. On September 18, 2012, Lim announced that he has picked 6th District Councilor
Lou Veloso to be his running mate. Lim noted that Veloso is the councilor that emerged with the most votes in the last local elections. On October 1, 2012, during the first day of filing of certificate of candidacies, Lim and Veloso, along with their ticket's 36 city council bets, filed their certificate of candidacies at the
Commission on Elections (COMELEC) field office in Arroceros, Manila. Lim is supported by all but one of the incumbent congressmen of Manila - Benjamin Asilo of the 1st District,
Carlo Lopez of the 2nd District, Zenaida Angping of the 3rd District,
Trisha Bonoan-David of the 4th District, and Sandy Ocampo of the 6th District. 5th District Representative
Amado Bagatsing originally supported him but endorsed Estrada instead. Lim also said that his 2013 campaign will be his last as he intends to retire from politics in 2016. He had previously served as mayor from 1992 to 1998,
Secretary of the Interior and Local Government under Estrada from 2000 to 2001, lost the mayorship to Estrada ally
Lito Atienza in 2001, elected Senator
in 2004 under the Estrada-backed
Koalisyon ng Nagkakaisang Pilipino, and retook the mayorship from Atienza's son
Ali in 2007, then successfully defending it against Atienza himself
in 2010. A day later, Estrada and Moreno filed their certificate of candidacies. Estrada left his home at
Santa Mesa with Moreno aboard his
jeepney he made famous during the
1998 presidential election. Estrada drove the jeepney to the COMELEC office at Arroceros; the
United Nationalist Alliance-backed Estrada ticket includes 29 of the incumbent 36 councilors. The contest between Lim and Estrada has been billed by many as "Dirty Harry vs. Asiong Salonga", with Lim being previously referred to as "
Dirty Harry", and Estrada having played Asiong Salonga in a movie. Aside from Lim and Estrada, other candidates include Marino Magallanes, a fortune teller from
Quiapo, mechanical engineer and
perennial candidate Onofre Abad, lawyer Felix Cantal, Samuel Gabot, Rodolfo Lim and driver Fidel Cruz. On January 7, 2013, the
Sandiganbayan ruled to dismiss via technicality a petition disqualifying Estrada from running due to a condition from his
pardon granted by President
Gloria Macapagal Arroyo that said he would not seek elective office. However, he faced other disqualification cases from the same issue at the Commission on Elections and at the Regional Trial Court. On January 16, the commission disqualified all of the mayoral candidates, save for Estrada and Lim, and declared them as "nuisance candidates." The two camps signed a covenant for peaceful elections at the
Manila Police District headquarters on February 15, 2013.
Commission on Elections chairman
Sixto Brillantes and Parish Pastoral Council for Responsible Voting chairman Henrietta de Villa witnessed the signing, which were also attended by the rest of the slates, including their running mates. A day later, the police arrested Moreno and five other UNA candidates for the city council for alleged illegal gambling. Estrada later said he may file charges against the police who arrested his running mate. The police arrested the group after they proceeded to hold a
bingo game, which the police had said to be illegal, after promising they would hold a raffle instead. Moreno and the other candidates were freed after the Manila Prosecutor's Office ruled that there was not enough evidence to prolong their detention. Moreno maintained that the bingo game is not illegal after President
Ferdinand Marcos classified it as a parlor game. Brillantes later said that Moreno's group did not violate any election law when they held a bingo game as the campaign period for local elections has not yet started. The Manila
Regional Trial Court dismissed another disqualification case against Estrada on March 4. Judge Marivic Umali heeded Estrada's lawyer Frank Chavez that the Commission on Elections and not the court had jurisdiction on the case. On April 1, the commission dismissed Estrada's last disqualification case. ==Opinion polling==