KUALA LUMPUR - Malaysia's ruling party Umno is "broken" and loyalty among its leaders is driven by money, says former Prime Minister Mahathir Mohamad in his latest criticism of the party he used to lead and the government of incumbent premier Najib Tun Razak, media reports said on Sunday.

In a four-part interview uploaded on a blog named Din Turtle over the weekend, Dr Mahathir insisted that the ruling party is headed for doom when asked for his response to calls from party stalwarts for him to reconcile with Mr Najib, who also serves as Umno President.

"Umno is already broken," the 89-year-leader told his interviewer in one clip, according to the Malay Mail online.

"The Umno that I led before was quite powerful. If you look at our assemblies, the spirit was there.

"The Umno now is about money. Its leaders are loyal because they get something... contract, the ones who get posts all get money (too).

"But when you do that, you give to the chief... what about the rest?" he asked.

Dr Mahathir has recently repeatedly attacked Mr Najib over a long list of issues, from the controversial deals made by the poor-performing state-owned investment agency 1Malaysia Development (1MDB) to tougher sedition laws approved on Friday by Parliament.

He has said Malays are deeply disappointed with Mr Najib's rule, and suggested that Umno's Barisan Nasional (BN) coalition could end up losing power in the next general election.