Cheras Umno division leader Syed Ali Al-Habshee is the latest to announce his resignation from the party.
According to the once-vocal Umno man, the decision was based on safeguarding the interest of the Malays in the Federal Territory.
"I would like to officially announce that I have made a decision with a heavy heart, to quit Umno,” he was quoted as saying by Sinar Harian this afternoon.
Last Saturday, tongues started wagging when Syed Ali attended Amanah's anniversary celebrations.
Responding to the latest resignation, Khairy Jamaluddin said the Umno annual general meeting this weekend must serve as a “turning point” for the party.
“If the AGM fails to provide a clear direction for the members and rakyat, I am worried that more will leave Umno,” the Rembau MP tweeted.
Several quarters have blamed the leadership of current Umno president Ahmad Zahid Hamidi for the exodus, which included several big names such as former ministers Mustapa Mohamed and Anifah Aman.
Zahid had defeated Khairy and another challenger, veteran Tengku Razaleigh Hamzah, for the Umno president post in June.
Since then, he has rarely been on the media radar whereas his predecessor Najib Abdul Razak continues to hog the limelight.
Meanwhile, Umno secretary-general Annuar Musa told Malaysiakini that he has heard about Syed Ali's resignation, but has not received anything in black and white.