In separate statements, Batu Kawan DAP Youth and Bukit Mertajam DAP Youth also slammed the aide, whom they identified as Tan Khong Chong,  claiming he behaved rudely and inappropriately.

Batu Kawan DAP Youth said Tan’s actions had sullied the party’s image and called for tough disciplinary action to be taken immediately for breaching party ethics.

“We will not tolerate any form of insult or open attacks aimed at affecting the credibility of the Penang DAP chief.

“Party members must respect the state leaders and be on their best behaviour.”

Bukit Mertajam DAP Youth said any dissatisfaction within the party should be expressed through proper channels and not via “inappropriate behaviour” in public.

They also said that any member who publicly challenges the state chairman is in essence challenging the authority of the entire DAP, something which cannot be tolerated.

“We urge the party to probe the matter. We will send a letter to the state committee to demand an investigation.”

Last night, Malaysiakini reported that the aide hurled a vulgar insult at Sim and called him a traitor.

Witnesses said the incident occurred when Sim was greeting supporters at a dinner. The man approached Sim and berated him for nearly 10 seconds, and also accused him of attempting to undermine Lim.

FMT has reached out to Tan and Sim for comment.