Mexico's main conservative party and a center-left party have struck an alliance to run a joint candidate in the 2018 presidential race, though so far they're disagreeing on what their coalition should be called.

The conservative National Action Party is calling it the Citizen's Front of Mexico. The Democratic Revolution Party says it's the Broad Democratic Front.

Both parties are hoping to unseat the ruling Institutional Revolutionary Party next year. Former PRI candidate Andres Manuel Lopez Obrador is also seen as a formidable contender as the standard-bearer of his upstart Morena party.

Democratic Revolution leader Barrales said Tuesday that "we know we don't have the same ideas, but we pursue the same goals."