The Prosperous Justice Party has repeated its threat to quit the coalition government if President Susilo Bambang Yudhoyono reduces the party's number of cabinet positions.

The Islam-based party, known as the PKS, currently has four cabinet posts but has often proven to be more of a thorn in Yudhoyono's side rather than a committed coalition partner.

Despite ongoing criticisms of controversial Communications and Information Technology Minister Tifatul Sembiring, speculation is pointing to Minister of Research and Technology Suharna Surapranata as potentially being the one on his way out.

One name that has been suggested as his replacement is Berth Kambuaya, the rector of Cendrawasih University in Jayapura, Papua, though he is expected to be named environment minister.

Rumors doing the rounds also suggest that if Kambuaya was appointed to either position, it would be unlikely Yudhoyono would have two Papuans in his cabinet, meaning Transportation Minister Freddy Numberi could be shown the door. Former Army Chief of Staff Gen. George Toisutta has already been mooted as a replacement.

Social Affairs Minister Salim Segaf Al Jufri, one of the PKS's four ministers, said all of the party's cabinet members would obey instructions to resign in the event even one of them was replaced.

Yudhoyono is expected to announce his new cabinet line-up at 8 p.m. The ministers of trade, state-owned enterprises, justice and human rights, administrative reform and public housing are expected to be replaced.