A growing leadership battle within Spain's main opposition Socialist party could tear the 137-year-old organization apart and hurl the country toward an unprecedented third election in a year.

Party heavyweights aired their differences across the media Friday, indicating a crucial weekend federal committee may be unable to resolve the schism between those for and against leader Pedro Sanchez.

The split was triggered by a party executive board revolt against Sanchez on Wednesday.

The burning issue is whether the party should help end Spain's nine-month political impasse by allowing acting conservative Prime Minister Mariano Rajoy to form a government.

Sanchez insists the party agreed to block Rajoy. If he prevails, Spain is unlikely to be able to form a government before an Oct. 31 deadline and fresh elections will be called.