In the 2008 general election, Er representing DAP had created history by winning the Bakri constituency to be the first MP from opposition, other than the governing Barisan Nasional (BN) coalition or its predecessor, the Alliance Party, from the Johor state ever elected to the Parliament of Malaysia since Independence.

[2] Upon his election, Er, a Mandarin speaker, stated that he was planning to hire private tutors to improve his Malay and English language skills to communicate more effectively with his constituents.

[3] The Star columnist Lee Yuk Peng has said that Er has impacted parliament with his "efforts to bring issues close to the heart for parliamentary deliberation" and had the "reputation of being a hard working and dedicated MP" prepared to ask questions in parliament despite his lack of proficiency in Malay.

[4] Persistence paid off for Er when his second emergency motion on the accident involving an express bus was allowed to be debated in Parliament on 3 November 2010.

Somehow Er did not seek a third term reelection for his Bakri parliamentary seat in the 2018 general election to make way for Yeo Bee Yin, the former Selangor State Legislative Assemblywoman of Damansara Utama who successfully defended the seat for DAP.