With the registration process for Indonesia's presidential election in February underway, Defense Minister Prabowo Subianto has picked outgoing leader Joko Widodo's eldest son as his running mate.

Prabowo, who heads the third-largest Gerindra party, made the announcement on Sunday. He said he will be nominated as the presidential candidate and Gibran Rakabuming Raka will be put forward for the vice-presidency.

Gibran is mayor of Surakarta City in Central Java. The choice of the 36-year-old running mate could boost Prabowo's campaign due to Joko's popularity.

The announcement comes after a controversial judgment by a top court that changed the eligibility rules. The new rule lets those who served as regional leaders run even if they're under 40, which is the normal age requirement.

While the selection of Gibran has drawn a lot of attention, President Joko says he has no involvement with the candidates. He said on Sunday parents should "pray and approve everyone's decision. We don't interfere too much in matters that have been decided by our children."

Joko's support rate remains high. Analysts say the choice of his son as veep candidate may not only benefit Prabowo's campaign, but also be a chance for Joko to retain influence.

The latest opinion poll gives the Prabowo-Gibran ticket a comfortable lead. They're followed by the Ganjar-Mahfud pair and the Anies-Muhaimin matchup.