A Malaysian official says the ruling party has sacked two powerful former ministers after they openly supported the opposition in the run-up to next week's national election.

Federal Territories Minister Adnan Mansor says former Trade Minister Rafidah Aziz and ex-Finance Minister Daim Zainuddin have been dropped from the United Malays National Organization after they attended an opposition rally on Friday. UMNO is the linchpin of the ruling coalition.

Adnan said Saturday that former Information Minister Rais Yatim is also being investigated over criticism he posted on social media.

Analysts say the three veteran politicians' support of the opposition added weight to former Prime Minister Mahathir Mohamad's bid to unseat the country's long-ruling coalition in May 9 polls. Mahathir now heads a four-party opposition alliance.