社会主义阵线
After their release, Lim and his affiliates would later challenge Lee's leadership in the PAP, leading to the expulsion of most of the left-wing members from the PAP in 1961. The expelled members would then form the Barisan Sosialis, and posed a strong challenge against the PAP on the next election in 1963; although being crippled by Operation Coldstore, they came closer to removing the PAP from power than any other party to date.