Malaysia's iconic former leader Mahathir Mohamad on Friday signed a declaration with members of both opposition and ruling parties to remove Prime Minister Najib Razak.
If Najib is allowed to remain in power, the damage from the scandal related to the deeply indebted state fund 1MDB will become worse, Mahathir said.
"We must rid ourselves of (Najib) as the prime minister of Malaysia," he said.
The declaration, which Mahathir read aloud in English at a press conference, said that Malaysia had descended to become one of the 10 most corrupt countries in the world under Najib's leadership; Mahathir didn't provide a source for that figure, although he noted that Malaysia fell four slots in the 2015 Transparency International corruption perception ranking from 50 to 54.
Najib's office didn't immediately respond to an email requesting comment.
In a statement emailed to CNBC, a Malaysian government spokesperson said: "Today, Tun Mahathir and his former enemies have demonstrated the depth of their political opportunism and desperation.
"There is an existing mechanism to change the Government and Prime Minister. It's called a general election. And it is the only mechanism that is lawful, democratic and fulfils the people's will.
"In 2013, the Malaysian people expressed their will and elected the current government, led by Prime Minister Najib Razak. If Tun Mahathir wants to change the Government, he must follow democratic process and await the next election, in line with Malaysia's laws and Federal Constitution."
Reuters also reported that opposition leader Anwar Ibrahim, who Mahathir removed as deputy prime minister in 1998, issued a statement from jail saying that he supported the push to remove Najib.
Najib has been under pressure since the Wall Street Journal published a report in July alleging that nearly $700 million had flowed from the 1Malaysia Development Berhad (1MDB) fund to Najib's personal bank account.
Najib has repeatedly denied wrong-doing and, under pressure from the WSJ report, said at the time the funds were a private donation from a Middle Eastern country he declined to name. In January, Malaysia's Attorney General Mohamed Apandi Ali told an unscheduled press conference that Saudi Arabia's royal family gave Najib a $681 million gift that was subsequently partially returned.