MEXICO CITY (Reuters) - Mexican opposition leader Ricardo Anaya said on Sunday he would seek to win the presidency in a left-right alliance after stepping down as head of the conservative National Action Party (PAN). Anaya resigned as leader of the PAN on Saturday, a day after his party officially joined forces with the center-left Party of the Democratic Revolution (PRD) and the Citizens Movement party in the  For Mexico in Front  coalition. If selected, Anaya will likely take on leftist former Mexico City Mayor Andres Manuel Lopez Obrador, and former Finance Minister Jose Antonio Meade, who is seeking the nomination for the ruling centrist Institutional Revolutionary Party (PRI). Meade, who has served in both PRI and PAN administrations, resigned as finance minister in November and PRI officials hope he will help the party recover from a spate of corruption scandals.  This corrupt and inefficient PRI government has been an absolute national disaster,  Anaya said on Sunday, adding that his own party did not make fundamental structural changes during its two presidential terms from 2000 to 2012. Anaya saw a split in his party in October when former first lady Margarita Zavala left to launch a bid for the presidency as an independent candidate. Zavala, the wife of former President Felipe Calderon, said she quit the PAN because the party base had been subordinated to the interests of its leadership. The left-right coalition on Friday presented its official request with the electoral institute to compete in the July 2018 vote. The group must still pick its leader, with Anaya, who had been leader of the PAN since 2015, considered the front-runner. Anaya, 38, has faced criticism in the Mexican press for his family s  inexplicable  level of wealth, although he denies any wrongdoing. In a voter poll published on Wednesday, Anaya came in second behind Lopez Obrador, who leads the National Regeneration Movement (MORENA) party, but ahead of Meade. Mexico City Mayor Miguel Angel Mancera, who was seen as a contender for the coalition, said on Saturday he would not run and criticized what he said was an undemocratic selection process. 