Muar MP Syed Saddiq Syed Abdul Rahman has expressed disappointment with Prime Minister Tan Sri Muhyiddin Yassin whom he regarded as his 'father' for allegedly betraying their party's founding principles when the latter chose to work with 'the kleptocrats'.

The former Youth and Sports Minister said Muhyiddin had formed an illegitimate "back door government" without the knowledge of former prime minister Tun Dr Mahathir Mohamad.

"He is like my own father and is one of the reasons why I decided to enter politics.

"He is one of the most vocal opponents of the global kleptocrats. He was fired by his party for challenging the kleptocrats (in UMNO)," he said in an interview with host Mehdi Hasan on Al Jazeera's news programme UpFront on Saturday.

Muhyiddin was sacked from his post as deputy prime minister by former prime minister Datuk Seri Najib Tun Razak in 2015 for violating party discipline.

Syed Saddiq also told of the threats he faced when opposing 'the kleptocrats' and the rewards he was offered if he were to join the group.

“What truly disappoints me is that today, my very own leader, my 'father', decided to open the door of the Malaysian government and democracy to the same kleptocrats that threatened me and my family, who sacked him and threatened his family.

"And now he (has) aligned himself (to them),” Syed Saddiq said.

In the interview, Mehdi also raised the question on the stance taken by Parti Pribumi Bersatu Malaysia (Bersatu) on racial politics.

"Is it not the problem arose due to the 'undemocratic' collusion is led by a prime minister who once said he was a Malay first in 2010?

"However, he is one of the top leaders in your own party, not the opposition," Mehdi told Syed Saddiq.

Syed Saddiq said of racial politics, “I have always been a Malaysian. However, I don't think it is wrong to feel proud of my race.

"It is very important for me to ensure that the less affordable ones and those from poor families deserve help. Unfortunately, most of them are ethnic Malays."

He further said the matter and his stand against 'the kleptocrats' became the basis behind his support given to his 'father', Muhyiddin.

Former Prime Minister Tun Dr Mahathir Mohamad had earlier described Muhyiddin as a "traitor" who cared more about politics than principles.

This followed the political turmoil that saw Dr Mahathir resign as Prime Minister and Bersatu Chairman on February 25.