SUPP, formed in 1959, is the oldest political party in Sarawak.
Its top leadership had gathered at their headquarters in Kuching on May 14 and decided that SUPP needs to chart a new direction following its dismal showing in the May 9 polls.
A top SUPP source told The Star on Thursday (June 7) that party leaders will convey their decision to Sarawak Barisan chairman Datuk Amar Abang Johari Openg.
“We in SUPP have already made a decision within the party that we need to leave the Barisan coalition.
“We feel that being part of the Barisan coalition now may not be conducive as the party charts its direction ahead.
“The intention to leave Barisan has been agreed among the SUPP’s top leadership.
“On June 12, SUPP will attend the state Barisan supreme council meeting, and after that, we will officially convey to Abang Johari our decision to leave the coalition.
“We will listen to what Abang Johari has to say in his capacity as state Barisan chairman and chief minister, but as of today, SUPP has made an internal decision to leave,” the source said.
Asked if SUPP would apply to join Pakatan Harapan after leaving Barisan, the source said that the matter had not been decided.
SUPP has only one parliamentary seat left, Serian.
In GE14, it lost in Bandar Kuching, Stampin, Sarikei, Sibu, Lanang and Miri.
The Star learned that on June 12, the other three Sarawak Barisan coalition partners will also decide on whether to leave Barisan or not.
These are Parti Pesaka Bumiputra Bersatu (PBB), Parti Rakyat Sarawak (PRS) and Progressive Democratic Party (PDP).
Sarawak Barisan has 19 out of the total 31 parliamentary constituencies in the state.
PBB has 13 seats, SUPP one, PRS three and PDP has two.