"We are measured by our ability to rule," Greek Prime Minister Alexis Tsipras warned his fellow party members in February 2015. That was only a few weeks after the young, radical prime minister had taken office and had already suffered his first serious setback: Greek debt would not be restructured, and instead, the loathed credit agreement would be extended. Inner-party opponents tested his strength and in the summer of 2015, a split occurred in Syriza.

The radical left-wing group in the party, headed by then energy minister Panagiotis Lafazanis, left Tsipras and threatened to establish committees to fight against the EU-dictated austerity program. Lafazanis tried his luck with his own party at the snap election – with little success - and was subsequently receded into political oblivion. Ever since then, Syriza has been a work in progress. A party conference was supposed to establish power structures, but was constantly postponed over the past months.

Now, the time has come. On Thursday evening, 3,300 Syriza delegates from all over Greece will meet in Piraeus. To kick off the party congress, Tsipras wants to present his political platform and commit party members to his line. This is no easy task. "The Syriza party is an unusual and unique phenomenon in Europe: It consists of different orientations and that makes for its richness, but also its weakness," explained Nikolas Voulelis, director of Greece's left-leaning newspaper "Efimerida ton Syntakton" (The Editor's Newspaper).

Contrary to some expectations at home and abroad, Syriza will not change its approach at this convention and shift to social democracy, but instead, remain faithful to its ideology, said Voulelis in an interview with Deutsche Welle.

However, how does the government's commitment to its ideology fit with the implementation of the much-hated austerity policy? Voulelis believes that the EU austerity agenda was a "defeat" for Syriza. But he also said, "In addition or in parallel with the government's policy, a left-wing agenda must be put on the table. In this respect, the party must lead the way with its own ideas and proposals."

Scheming behind the scenes

Tsipras himself promised "a left, parallel program for the socially vulnerable" when he backpedaled once more and was forced to consent to more austerity measures. The Athens-based political scientist Lefteris Koussoulis believes that the left-wing prime minister wants to prove his versatility again by accepting criticism from party hardliners and declaring it to be a matter of personal importance. "A touch of revolution is in the air and in Piraeus; we will see the old Tsipras," said Koussoulis in an interview with DW. Tsipras will distance himself from his government policies, he says, and will reassure the delegates that he has not betrayed his left-wing past and vision. "Sins are committed in the government but the party saves the comrade's soul," said the analyst.

Moreover, Tsipras has taken precautions to secure broad majorities in party committees. The number of members in Syriza's central committee is to be reduced from 201 to 150. Effective immediately, only 25 percent of the positions will be awarded to candidates who have government responsibilities, like those who hold parliamentary seats, or are employed in state institutions. This new regulation would shut out old guard politicians from the committee, probably allowing Tsipras supporters to move up.

"Alexis Tsipras will be given a strong mandate as he will be re-elected as the head of Syriza with an overwhelming majority," said the EU parliamentarian Dimitris Papadimoulis. The most significant opposition group within his party is the "Movement of 53", which consists of 53 Syriza politicians who in principle vote for the austerity measures in Greece but demand consistency in their implementation.

Finance minister Euclid Tsakalotos is actually a leading figure in this group. He recently caused a stir by making a somewhat casual comment about whether Greece was able to survive in today's euro zone. Subsequently, the minister said he felt misunderstood and that his words were taken out of context. Will Tsakalotos and his followers put the dogmatic agenda on the table again? "I don't think that the 'Movement of 53' poses a threat. Tsipras actually has the party under control," said Nikolas Voulelis.

Tsipras lambasts the opposition

Tsipras' new-found confidence also allows him to harshly criticize the conservative opposition, said the political scientist Koussoulis. The head of Syriza has drawn a clear line between his party and the opposition: We are the good guys; you are the corrupt ones.

On Tuesday, at the parliamentary debate on corruption, Tsipras revealed a bit of what is to come. He lambasted the head of the conservative opposition as a "child of Siemens," clearly referring to the Siemens bribery scandal in Greece. In the eyes of the prime minister, both former Greek governments, conservatives and Social Democrat, played their part in it.  Political scientist Koussoulis believes that Tsipras will present himself as an anti-corruption fighter. After all, "it is the task of party conferences to campaign against reality."