Dr Mahathir Mohamad is often accused of masterminding a campaign against Prime Minister Najib Abdul Razak to orchestrate his son Mukhriz’s political ascension.

However, the former premier denied this, claiming that he is acting in the interest of the nation.

“I am not concerned about Mukhriz’s future. I am more concerned about stopping Najib from destroying this country,” he said in his latest blog post.

Mahathir accused the prime minister's “henchmen” of repeating this allegation to divert attention from the alleged wrongdoings of their boss and no amount of explanation would stop them.

He also claimed that when Najib was unable to solicit unqualified support from Mukhriz, the prime minister “engineered” his removal as Kedah menteri besar.

“I could have easily helped Mukhriz by ignoring Najib’s wrongdoings and continuing to support him. But I did not do this...,” he added.

Mahathir also pointed out that he could have allowed his sons to contest for office in Umno or become election candidates when he was prime minister and party president.

“But Mukhriz could not even become a member of Umno because the Kubang Pasu division of which I was head, refused to accept him.

“It was after the Umno headquarters directed the division that he was admitted as a member, just before I retired,” he said.

Mahathir pointed out how his son stood for a parliament seat in 2008, and was appointed as a deputy minister following his victory.

“At that time, Kedah had a PAS government because Umno under Mahadzir Khalid lost the state in 2008.

“In the 2013 (general) election, Mukhriz chose to contest for a state seat.

“Kedah people believed if he would be appointed menteri besar, BN would defeat PAS and regain Kedah. Najib apparently agreed.

“BN won Kedah in the 2013 election. Mukhriz was appointed menteri besar,” he said.

However, ties began to strain and subsequently severed between Mahathir, his son and Najib when the 1MDB issue erupted.

“When the 1MDB scandal exploded I stopped supporting Najib. Mukhriz did not show full support for Najib.

“He was critical of Najib’s explanation about the RM$2.6 billion in Najib’s private accounts,” said the former premier.

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

Attorney-general Mohamed Apandi Ali has also cleared Najib of any wrongdoing.