陈庆炎
The 2011 presidential election was contested by Tony Tan Keng Yam, Tan Cheng Bock, Tan Jee Say and Tan Kin Lian. All candidates except Tan Jee Say were former members of the PAP, whose closest relation to the party was when he served as then-Deputy Prime Minister Goh Chok Tong's principal private secretary from 1985 to 1990. The election was won by Tony Tan with a margin of 0.34% over Tan Cheng Bock.