Perak MCA chairman Datuk Dr Mah Hang Soon said Nga had "exploited" the appearance of DAP's Teluk Intan parliamentary seat candidate Dyana Sofya Mohd Daud to win support from the people.
"Nga had claimed that if Dyana Sofya wins, Teluk Intan would have the prettiest MP ever.
"This is not the first time for Nga to make discriminatory and sexist remarks against women. During the Kajang by-election, he had poked fun of Barisan Nasional candidate Datin Paduka Chew Mei Fun by describing her as a maid and was later condemned for his own action," he said in a statement on Wednesday.
Mah said Teluk Intan needed a candidate with calibre and candidates should compete on ideology and political views rather than their appearances.
"I find it a great insult to the female candidate if she can only rely on her appearance to win the by-election," he said.
Mah urged Nga to respect women and discuss about the candidate's political ideology and manifesto since DAP had yet to showcase its manifesto even at this stage.
Gerakan president Datuk Mah Siew Keong will square off against DAP's Dyana Sofya Mohd Daud in the by-election following the passing of incumbent Seah Leong Peng earlier this month due to cancer.