As it prepares to celebrate its third birthday and inches closer to a crux congress in February, supporters are watching in dismay -- and opponents with glee -- as Podemos chief Pablo Iglesias spars with his deputy Inigo Errejon over what strategy to take.
The dispute between the once-inseparable pair has forced party members into one faction or another, played out on social media and in the press, gaining such traction that an apologetic Iglesias warned it could "destroy" Podemos.
"It's one thing to have differences, another thing is this hugely exaggerated internal battle," says Gabriel Colome, politics professor at the Autonomous University of Barcelona.
"They are reproducing age-old behaviour patterns typical of other parties." He warned "they do this right, or this project is going to explode."
After its emergence in January 2014, Podemos rose at meteoric speed to score big in elections just under two years later. In those December 2015 polls, it became Spain's third political force, putting an end to the two-party system but also leaving no grouping with any absolute majority.
As coalition negotiations dragged on, rumours of a rift between the charismatic, pony-tailed Iglesias and his baby-faced number two started to emerge. But it was only after repeat June elections saw a Podemos-led coalition
lose votes that the rift between the combative Iglesias and more moderate Errejon leapt to the fore.
While the aim had always been to overtake the Socialists and become Spain's main left-wing force, exactly how to achieve this was a subject of much debate. Should the party continue its struggle for change -- but from within institutions it now occupied such as parliament, and in a moderate way that would attract Socialist voters too, as Errejon advocated?
Or should it also go back to the streets, keep resisting and shaking things up as a protest party, as Iglesias wanted?
These divergences broke out into the open in September in a war of tweets.
"We are already scaring the powerful, that's not the challenge. The challenge is to attract those people who suffer but still don't trust us," Errejon wrote.
"Yes comrade @ierrejon but we stopped attracting one million people in June. We seduce more by speaking clearly and being different," Iglesias retorted.
From then on, divisions played out publicly, continuing even as the Socialists (PSOE) imploded and the conservative Popular Party came back to power at the head of a minority government with little support -- all of which could have profited Podemos.
The situation left supporters in a state of distress. Once an enthusiastic Podemos militant, Tristan Duanel has now stopped all activities for the party, as have others he knows.
"We have ended up really bitter," he says.
Such has been the dismay that Iglesias felt compelled to apologise last month.
"If the press and social media continue to be a stage for us to try and air our dirty laundry, we will destroy Podemos," he recognised.
The issue will likely be set to rest at the party congress in February, when Podemos members will vote for a new leadership council, a process that may or may not unseat Iglesias, and for what direction to take.
With this in sight, Errejon's clan published a policy document on Friday acknowledging there were "two strategies" vying for power.
On the same day, Iglesias and his team published their own document, in which they warned that "only a united and strong Podemos will be able to rule."
To further complicate matters, a third movement which is neither behind Iglesias or Errejon has emerged as kingmaker.
The more radical anti-capitalists, as they call themselves, want to take to the streets again like Iglesias.
But they also feel that the party's power is currently in the hands of too few people, calling for decentralisation... like Errejon.
"They will be pivotal," says political analyst Pablo Simon. He also struck a positive note, saying all was not lost for Podemos and now was the time to resolve their differences.
"The PSOE hasn't recovered and cannot challenge them much, and we're far from new elections," he said.