Dr Mahathir Mohamad believes the rulers will intervene to stop the alleged "abuse of power" by Prime Minister Najib Abdul Razak.

He said this is despite no provision in the law allowing such intervention.

"Nevertheless, there are ways and means for the rulers to save the country form the abuses of power by Najib.

"The people look up to the rulers to save Malaysia. I am sure the rulers will not fail them," he added in a blog post today.

The former premier said this is why the Citizens' Declaration, which has reportedly been signed by more than a million Malaysians, would be sent to the rulers.

Mahathir reiterated that sending the declaration to the rulers was the last resort.

The declaration, among others, called for Najib's resignation amid allegations of corruption.

This includes the 1MDB imbroglio and RM2.6 billion found in the prime minister's bank accounts.

Najib has been cleared of wrongdoing by the attorney-general over the RM2.6 billion and RM42 million funnelled into his accounts from state firm SRC International.

The prime minister has also denied abusing public funds, and blamed such allegations on Mahathir and those conspiring to topple him from power.

International agencies including in Singapore, Switzerland and the United States are investigating the 1MDB trail of funds. One former banker has been charged in Singapore for charges related to the 1MDB probe, while authorities ordered the shutdown of BSI Bank branch in Singapore.

Switzerland has also started criminal proceedings against the 143-year-old Swiss bank that had earlier been under the United States Justice Department radar for assisting in tax evasion by moving funds across borders incognito.