(Reuters) - The elder statesman of Mexico's main leftist political party resigned his membership on Tuesday, citing "profound differences" with the party's leadership over how to root out what he has described as worsening corruption within its ranks.
Cuauhtemoc Cardenas, a three-time presidential candidate and son of former president Lazaro Cardenas, said in a letter to the leadership of the opposition Party of the Democratic Revolution (PRD) that his decision was irreversible and follows calls he made last week for party leaders to step down.
PRD leaders did not resign but instead held talks with Cardenas earlier on Tuesday aimed at defusing the political crisis.
The PRD, which Cardenas helped found in 1989, has been under fire over the abduction in late September of 43 students by police in the southern state of Guerrero, where both the mayor and state governor at the time were PRD members.
The government says the students, who attended a radical leftist teachers college, were seen as a threat by the mayor, who was in league with a drug gang.
Guerrero police handed over the students to the gang, which apparently murdered them and then burned their bodies, according to the attorney general.
Cardenas, 80, is the not the first high-profile PRD leader to distance himself from the party.
Leftist firebrand Andres Manuel Lopez Obrador, the PRD's standard-bearer in the last two presidential elections, resigned from the party in 2012.
Lopez Obrador, who nearly won the 2006 election, has since founded a rival leftist party.
Despite the blow the crisis in Guerrero has delivered to President Enrique Pena Nieto's ruling Institutional Revolutionary Party, the PRD and the conservative National Action Party have both suffered major divisions over the past couple of years.
(Reporting by David Alire Garcia; Editing by Paul Tait)
