Ling was the chairman of the Singapore Democratic Party in 1991 when, in a surprise result, he defeated the incumbent MP from the governing People's Action Party (PAP), Dr. Seet Ai Mee, to win the constituency of Bukit Gombak at the general election.

Ling was one of three SDP MPs to be elected – with the party's leader Chiam See Tong retaining his seat in Potong Pasir, and Cheo Chai Chen winning in Nee Soon Central.

[4] Ling was defeated in his bid to be re-elected as MP for Bukit Gombak at the 1997 general election, losing to the PAP's Ang Mong Seng.

Ling stood in Cheo's former constituency of Nee Soon Central, and was defeated by the PAP's Ong Ah Heng.

After surgery to insert a feeding tube into his abdomen, he contracted pneumonia and died on 30 April 2021 at age 86.

[4] His funeral wake was held at Singapore Casket in Lavender Street on the following day and his cremation was at Mandai Crematorium on 4 May 2021.