As long as two to three months before former Prime Minister Mahathir Mohamad publicly attacked his successor, Najib Tun Razak, through his blog, the former premier sent Najib a letter bristling with a list of demands to change his ways.

Mahathir’s irritation has sputtered behind the scenes since before the disastrous May 2013 general election, in which the ruling Barisan Nasional lost the popular vote for the first time in 44 years although it retained its majority in parliament via gerrymandering. Since that time, bloggers deployed by Mahathir have made general attacks on the sitting prime minister, who took office in 2009 with Mahathir’s approval.

But for the first time he personally criticized Najib in his blog, Che Det, saying on Aug. 16 that he had withdrawn support. The campaign against Najib has been mounted now in advance of the November United Malays National Organization general assembly, where it appears Najib has an unassailable position as party president.

Mahathir was scheduled to leave tonight for London, where Najib and his wife Rosmah Mansor have been for the past several days after a holiday that began three weeks ago after Najib’s speech to families of the doomed MH17 airliner, which was brought down by a rocket over disputed territory in Ukraine on July 17.

In the letter to Najib, quoted to Asia Sentinel by a businessman with links to UMNO, Mahathir reportedly listed seven demands. Najib is said to have dispatched Tengku Adnan Tenku Mansor, the secretary-general of the United Malays National Organization, to see Mahathir, asking him to withdraw the letter. Mahathir refused, however, sources say. In the intervening weeks, nothing has happened.

Since Mahathir’s attack, the story has been playing out behind the scenes of the mainstream media, which are controlled by the political parties that make up the national ruling coalition. They have gone black, carrying only praise for Najib without mentioning Mahathir’s assault. Instead, the papers have merely included statements of support for Najib from leaders such as Foreign Minister Hishamuddin Hussein and others without mentioning the reason the support is needed.

Meanwhile the story has lit up the Internet, with independent news portals having a field day while Mahathir’s blogger allies including Rocky’s Bru, Outsyed the Box and others have defended him.

The demands listed in the letter included one that Najib reform the controversial 1MDB sovereign fund, which is deeply in debt after having funded a long string of controversial projects. It is said to be a major scandal sizzling out of sight and involving controversial Chinese playboy Taek Jho Low and Najib’s wife, Rosmah Mansor.

The octogenarian former premier also complained that not enough contracts let by Petronas, the national energy company, were going to build up Bumiputeras, mostly ethnic Malays, but instead were being let to more neutral parties. At one point in October of 2013, Mahathir actually resigned from Petronas, saying his doctors had advised him to slow down. But the real reason is said to have been his anger with Najib’s performance.

He also accused Najib of being too friendly with foreign governments including the United States over the bid to join President Barack Obama’s TransPacific Partnership Agreement free trade pact, and Singapore for bending to Singapore’s wishes and cancelling a controversial crooked bridge between the two countries over the Singapore Strait. He was also said to be miffed that Mahathir’s immediate successor, Abdullah Ahmad Badawi, attended a dinner with Obama during the latter’s Malaysia visit but that he wasn’t invited.

He also objected to the so-called one-off BRIM cash handouts that the government announced to households making less than RM3,000 (US$847) per month in 2012 as an election sweetener to alleviate the burden of a rising cost of living for low-income earners, saying it was breaking the budget. It ended up costing the treasury as much as RM4 billion.

He demanded that Malaysia Airlines, which is 70 percent owned by the Khazanah Nasional sovereign fund, be turned over to the private sector to attempt to right it after two disastrous crashes that took the lives of more than 500 people and which is almost moribund, losing billions of dollars. The private sector is said to be Syed Mokhtar al-Bukhairy, a longtime Mahathir crony who became the country’s richest Bumi tycoon, largely through government contracts.

Finally, Mahathir criticized Najib over the breakdown in racial and religious relations in the country, which have grown progressively more poisonous by the year. That seems to be a striking obtuseness on Mahathir’s part, since he has backed the Malay-supremacy NGO Perkasa, headed by firebrand Ibrahim Ali, and has made incendiary statements about racial superiority on his own. Prior to the 2013 general election, he sought to lead a major rally on May 13, the anniversary of 1969 communal riots that took the lives of hundreds. Najib forced the cancellation of the rally.

Allies say Mahathir’s aim is not to bring down Najib, but to apply enough pressure to force him into making deep changes in the way the government is being run. However, at the age of 89, having been out of power since 2003, and with few remaining allies in UMNO, it is questionable at this point how much clout he still has.

However, he has a formidable record, having forced the ouster of Tunku Abdul Raman and Hussein Onn as prime ministers before his own 22 year period in office, beat back challenges by UMNO stalwarts Tengku Razaleigh, the Finance Minister, and both Musa Hitam and Anwar Ibrahim as his deputy prime ministers, all of whom attempted to unseat him, and then forced the departure of the successor he picked, Abdullah Badawi. He is expected to mount a daunting campaign against Najib when the two return from overseas.