KUALA LUMPUR - Malaysian Prime Minister Najib Razak has been misled into thinking he still has public support, said former Malaysian premier Mahathir Mohamad.

Many people who have openly supported Datuk Seri Najib have privately backed calls for him to resign, he added.

"Every day when I meet people, they say, you are not alone," said Dr Mahathir, who has been relentless lately in his bid to force Mr Najib out of office.

"It cannot be me alone, that I'm the only one who wants him to step down. I think a lot of people want him to step down for the good of Umno and for the good of the country," Dr Mahathir said.

He was speaking to reporters yesterday on the sidelines of an anti-war forum, reported the Malay Mail on its website.

Dr Mahathir, Malaysia's longest-serving prime minister from 1981 to 2003, still commands much respect in the country.

He has publicly berated Mr Najib on a number of issues, including the troubles with the state-owned investment arm 1Malaysia Development Berhad (1MDB), which Mr Najib launched.

Dr Mahathir has also called on the ruling Umno party to remove Mr Najib or risk losing the next general election.

The intense barrage of criticisms fired at Mr Najib by Dr Mahathir has drawn even his foes to his side. On Saturday, Democratic Action Party adviser Lim Kit Siang said he was ready to put aside past problems and work with Dr Mahathir, if that is what it took to save the country.

But yesterday, Dr Mahathir ruled out working with the opposition to "bring Najib down", saying the problem is within Umno itself.

Meanwhile, in a seemingly cryptic message, Deputy Prime Minister Muhyiddin Yassin, who also spoke at the forum, praised Dr Mahathir for never shying away from telling the truth.

"Telling the truth and standing up has been your trademark since you were a young doctor and an ordinary Umno member... Let me assure you, sir, that you are not alone," said Tan Sri Muhyiddin in his keynote speech.

He added that Dr Mahathir had always stood up for what he believed in, and he saluted the former prime minister for having the guts to stand up to the world's superpowers in making a stand against war.

Mr Muhyiddin, viewed as the most likely person to replace Mr Najib if he were to step down, was once openly backed by Dr Mahathir as the most suitable candidate.

Although Mr Muhyiddin's comments at the forum stirred speculation that it was a nod to Dr Mahathir's recent calls for Mr Najib to answer his critics over the debt-laden state fund 1MDB and other controversial issues, Dr Mahathir quickly brushed aside the suggestion.

He told reporters after the event that Mr Muhyuddin was merely referring to Dr Mahathir's role in speaking up against war crimes. "It's about this war; I'm talking about the war, and I think he's supporting me for the war," Dr Mahathir said to reporters, according to the Malay Mail.