Prabowo Subianto, the incoming president of Indonesia, secured a parliamentary majority after the announcement by the party that supported his opponent in the February elections that it would be joining his big-tent coalition.
The NasDem party, which has 10% of the parliamentary vote, declared late on Thursday that it would back Prabowo's upcoming administration.
The Prabowo administration will gain authority over parliament as a result of the move, increasing its stake from 43% to 52%.
It is anticipated that the parliamentary majority will facilitate the legislative process, allowing for the passage of the 2025 budget, which will be announced on Friday by departing President Joko Widodo, also known as Jokowi.
On October 20, Jokowi's eldest son Gibran Rakabuming Raka, the vice president-elect, and former commander Prabowo will take the oath of office.
Surya Paloh, the head of Nasdem, told reporters on Thursday that he thought Prabowo's appointment would create a "calmer and more optimistic" environment and make the work of the upcoming administration easier.
Prabowo, whose coalition is made up of five political parties, is now in negotiations with the largest Islamic party in the nation, which holds a 10% parliamentary share.
In the past, NasDem supported Anies Baswedan, a vocal critic of the government and former Jakarta governor who was beaten by Prabowo in this year's presidential race.
The party has decided not to support Anies's November governor of Jakarta campaign after joining Prabowo. Kaesang, the youngest son of Jokowi, has been tipped to run for governor of Jakarta, or Central Java, in the past few weeks.
Anies, the front-runner in the Jakarta contest according to polls, has had trouble securing enough endorsements from parties.
This week, Anies said that he was certain he would eventually win the support of parties holding the necessary 20% of votes in the regional parliament, in spite of the pressure.
These occur in the aftermath of Airlangga Hartarto's abrupt resignation over the weekend from his position as leader of Golkar, the second-biggest political party in Indonesia and a close ally of Prabowo.
It was anticipated that Airlangga, an ally of Jokowi and Prabowo, would continue to serve as party chairman until the organization's December convention. Instead, that congress will be scheduled for next week, when the party's new chair will be chosen.
Analysts claim that Jokowi is trying to maintain control over Golkar in order to continue having influence once he leaves office after ten years in power.