Bickering between the pro-government NasDem Party and opposition parties Democratic Party and the Prosperous Justice Party (PKS) over their vice presidential pick again erupted this week, less than two months after Anies teased that he had made his choice.

NasDem made a gambit last year when it nominated Anies, widely seen as the opposition figurehead, risking its ouster from President Joko "Jokowi" Widodo's cabinet. The party has since repeatedly expressed concern over the future of the KPP.

On Tuesday, NasDem deputy chairman Ahmad Ali publicly called on Anies to refrain from choosing his running mate among the three party chairs in the KPP. Doing so would put NasDem, the Democrats and the PKS on an unequal footing in a clear “breach of commitment” of the electoral pact inked in March, Ali said.

Though Ali did not mention any names, many inferred his statement as a clear reference to chairman Agus Hartimurti Yudhoyono of the Democrats, which has been pushing him for Anies’ vice presidential pick.

The party also threatened to reevaluate its support for the alliance unless a running mate was declared in June.

As the KPP has intensified the search for its vice presidential candidate in recent months, ahead of the candidate registration slated to open in mid-October, Anies and Agus have flaunted their growing closeness through numerous joint appearances, leading to speculation that Anies might shortlist the Democrats’ chair.

Read also: Anies still mum on VP pick at Sunday's NasDem rally

The idea appeared to sour the mood of Anies’ main backer NasDem, which preferred naming an outsider to help make inroads in the key battleground provinces of Central and East Java, where Anies remains unpopular.

"We know that Anies’ weaknesses are, at least from what the surveys have shown, East Java and Central Java. Therefore we should look for figures [like] a Nahdliyin,” NasDem executive Effendy Choirie told a livestreamed discussion on Tuesday.

Effendy was referring to a term describing loyal members of the country's largest Muslim organization, Nahdlatul Ulama (NU), which present a potentially huge voting bloc in its stronghold province of East Java, the second most populous province after West Java.

“This would require acceptance from the three alliance members,” Effendy added.

Several NU-affiliated figures have been touted as potential running mates for Anies, including East Java Governor Khofifah Indar Parawansa, Coordinating Political, Legal and Security Affairs Minister Mahfud MD and Yenny Wahid, the second daughter of the late president and NU leader Abdurrahman “Gus Dur” Wahid.

All three have either turned down or responded elusively to the alliance’s offer, leaving Anies with a limited lineup composed of KPP figures: the Democrats’ Agus and PKS politician Ahmad Heryawan, a former West Java governor.

Read also: Anies burdened by political baggage in hunt for running mate

NasDem’s assertion over its preference came after the party uncharacteristically criticized Anies last week for vetting names without consulting the alliance’s member parties.

The Democrats have slammed NasDem’s suggestion to name a KPP outsider as “inappropriate”, arguing that the idea ran against political parties’ important role in "the recruitment and mentoring" of the nation’s future leader.

“This discourse is contrary to the nature of political parties, which are pillars of democracy and mandate holders as election participants,” said Kamhar Lakumani, the Democrats’ deputy head of elections and political campaigns.

The PKS meanwhile stressed that both party members and nonmembers should have the same right to bid for Anies’ running mate, with PKS executive Mardani Ali Sera noting that Anies needed someone who could both widen his appeal and help solidify the alliance.