Former Prime Minister Tun Dr Mahathir Mohamad had his membership in Parti Pribumi Bersatu Malaysia (Bersatu) dropped with immediate effect.

His son, Datuk Seri Mukhriz Mahathir who is deputy president, Datuk Amiruddin Hamzah, Dr Maszlee Malik dan Syed Saddiq Syed Abdul Rahman were also handed the same fate.

The decision was conveyed by Bersatu organising secretary Kapten Muhammad Suhaimi Yahya via letters to the five Members of Parliament (MPs) on Wednesday.

Muhammad Suhaimi said the decision was made because the five MPs refused to sit in the government bloc at a sitting of Parliament on May 18.

"At the Parliament sitting on May 18, 2020, the YBs were seated in a bloc that does not support the Perikatan Nasional government led by YAB Prime Minister Tan Sri Muhyiddin Yasin who is also the President/Acting Chairman (of Bersatu). Instead, the YBs were seated in the opposition bloc," he said.

He said Dr Mahathir's membership with the four MPs were immediately terminated in accordance with Clauses 10.2.2 and 10.2.3 of the Bersatu Constitution.