KUALA LUMPUR, Malaysia — A Malaysian official said Saturday 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.

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, said the party's secretary-general, Federal Territories Minister Adnan Mansor. UMNO is the linchpin of the ruling coalition.

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

"According to party constitution, when they sit together with the opposition and tarnish the party, they lose their right as members," Adnan told The Associated Press.

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, Asia's longest-serving premier when he retired in 2003 after 22 years, made a political comeback amid anger over a massive corruption scandal involving the 1MDB state fund.

Once an ally, Mahathir now heads a four-party opposition alliance seeking to oust Prime Minister Najib Razak.

Najib set up the 1MDB fund when he took power in 2009 and it accumulated billions in debt and is now being investigated in the U.S. and other countries for alleged cross-border embezzlement and money-laundering. Najib denies any wrongdoing.

Rashaad Ali, research analyst with S. Rajaratnam School of International Studies, said criticism by the former ministers against the government could win over some voters who were unhappy with the government but not convinced about voting for opposition.

"These ex ministers coming out could lend legitimacy to Mahathir and could have an impact on some fence-sitters," he said.

Still, analysts say it will be a tall task for Mahathir's opposition to win.