The main opposition Socialist Party wants the practice of holding primary elections for party leadership to be extended to all political groups and enshrined in the law, but the ruling Popular Party is opposed to such a move.
The Socialists have agreed that the next race for the leadership of the party will be held on the principle of one vote for all party members. "We are going to apply this in our case, but we're going to ask others to do likewise," EFE quoted Socialist congressional lawmaker Ramón Jáuregui as saying on Friday.
The former Cabinet chief in José Luis Rodríguez Zapatero's government said the change was needed to enhance transparency and restore waning public confidence in the political system. The move would involve amending the law on political parties.
The PP has historically opposed such a system. "Why do they want to impose their problems on other parties?" a member of the PP's national executive committee said Friday.
The idea of making primaries compulsory comes on the back of the Socialists moving toward allowing its regional branches to hold their own leadership votes.
Socialist leader Alfredo Pérez Rubalcaba has decided to bring forward the debate on introducing primaries to allow party members to elect their secretary-general. This rule change should only be made at a party congress, but with the next such event three years away, the national leadership has said it wants to tackle the issue this summer during the national committee meeting that precedes this fall's policy conference.
National party chiefs said they would back the changing of the rules to allow Socialist Party members to directly elect their leaders.
The announcement, made by party secretary Óscar López on Thursday, comes in the wake of the recent row caused by plans by the Galician branch of the party (PSdeG) to elect its own leader through primaries this June, in defiance of the central party line.
The PSdeG has since changed the date of its planned primaries to September 7, giving the central party time to change its statutes.