The chairman of Mexico’s main opposition Institutional Revolutionary Party, or PRI, has resigned amid a debt scandal in the northern state of Coahuila, where he served as governor until early this year.

Humberto Moreira said in an extraordinary session of the PRI’s political council that he will not allow “a media war” to damage his party, which is now widely expected to reclaim the presidency in next year’s elections.

In announcing his resignation, the 45-year-old party chief referred to electoral victories by the PRI this year in different regions of the country and expressed his support for its lone presidential candidate, Enrique Peña Nieto, the telegenic former governor of Mexico state who is the early frontrunner in the July 1, 2012, balloting.