KUALA LUMPUR (Apr 7): After being criticised for attacking the prime minister, Tun Dr Mahathir Mohamad hit back at his detractors saying that he only disagreed with Datuk Seri Najib Razak and not Umno.

“I am still an Umno member. My disagreement is with the leader, not with the party. I criticised the leader, not the party. It is simply because I want to see the party win.

“It will not win if Najib is the leader," Dr Mahathir wrote on his blog chedet.cc today.

Malaysia’s longest-serving prime minister has been chastised by Umno leaders and supporters for his open attacks against Najib.

Dr Mahathir defended his call for Najib to resign, saying that the latter was partly instrumental in asking for Abdullah to step down.

“As for the comment that it is unfair for me to ask Najib to step down as he was elected through democratic process, I would like to (say) Tun Abdullah was also elected but Najib was partly instrumental in asking him to step down

The latest salvo against Najib was that Umno and Barisan Nasional would lose the next general election if Najib did not resign as prime minister.

Najib, Dr Mahathir said, was worse than Tun Abdullah Ahmad  Badawi, the fifth Prime Minister who Dr Mahathir helped bring down and replaced with Najib.

“I had great hopes when Najib took over from Abdullah. But he did even worse than Abdullah, losing more badly in Selangor where he was the Head of UMNO. There are so many scandals surrounding him now.

“His popularity is now even lower than when he led the BN in 2013. In a number of constituencies the margins won by Barisan Nasional (BN) are very narrow.

“Sabah and Sarawak are now no longer safe, no longer BN’s fixed deposits. Is it too absurd to predict defeat for the BN in 2018?” Dr Mahathir wrote.

On April 2, Dr Mahathir had listed down in a blog posting various allegations made against Najib and noted that none had been answered adequately.

Dr Mahathir said these included the murder of Mongolian citizen Altantuya Shaariibuu and the claims made by one of her convicted murderers, former police commando Sirul Azhar Umar, who was a former bodyguard of Najib's.

Noting Sirul's claim that he had been "under orders" to kill Altantuya, Dr Mahathir said such an allegation ought to be investigated because Sirul had worked for Najib.

Dr Mahathir also delved into the problems surrounding 1MDB, the fund's purchase of government land at below market prices and its dubious deal with the little-known oil company, PetroSaudi International.

He also questioned the need for Putrajaya to give it a standby credit facility of almost RM 1 billion.

Dr Mahathir then questioned the source of funds for Najib's stepson, Riza Aziz, to purchase luxury properties in New York through businessman Low Taek Jho, better known as Jho Low.

He also mentioned the new private jet purchased for Najib, describing it as a "waste" since the government already had other jets.

Today, Dr Mahathir wrote that those accusations remain unanswered.

“A Prime Minister must be seen to be clean and able to explain and answer questions and to be good for the country.

“Najib cannot even answer and has not answered any question, beyond exercising elegant silence or saying the allegations are not true,” Dr Mahathir wrote.

“There is also an attempt to divert attention from my question by saying that I am siding with the opposition, even that I have become leader of the opposition.”