Spain's Socialist Party is facing strong internal discord as they vote to decide if they will keep or oust their leader Pedro Sanchez, who has been leading opposition to acting conservative Prime Minister Mariano Rajoy's efforts to build a minority government and end a nine-month political deadlock.

Sanchez insists he will continue blocking Rajoy. If he preserves his leadership in Saturday's vote by party members, Spain will be unable to form a government by Oct. 31 and a new round of elections will be called on Christmas day.

If his opponents win, a new party leadership might abstain from blocking Rajoy, resulting in an end of the deadlock.