Ezam Mohd Nor has left Parti Generasi Baru (NewGen) following frustrations over the delay by the Registrar of Societies (ROS) in having the party renamed as Parti Bebas Rasuah.
This is the fifth time Ezam has left a political party since 1998.
In a statement, Ezam also cited the "lack of positive indications" that NewGen's application to change amend its constitution would be approved by the ROS.
Ezam, who was NewGen's president, explained that changing the party's name was crucial because he and his party had the single goal of eradicating corruption.
"This (delay by the ROS) has made it difficult for us to move forward as a party that is specifically aimed at battling corruption."
"It halted our agenda of battling corruption which has put Malaysia in a critical state," he said...