In a shock announcement, Mr Low Thia Khiang has said he will not contest the post of secretary-general of the Workers' Party (WP) at its next Central Executive Council election, due next year.
He said this last night during a dinner to celebrate the party's 60th anniversary.
"We now have a team of younger leaders who are ready to drive the party forward... I will therefore not be contesting the post of secretary-general at the next party election," he said.
Mr Low, 61, took over as secretary-general from Mr J.B. Jeyaretnam in 2001.
The history books will remember Mr Low as the first opposition leader to win a Group Representation Constituency (GRC).
He led the team to victory in Aljunied GRC in 2011 and retained it at the 2015 election.
Political observer Derek da Cunha said: "It is no secret that there has been a clamour by one section of the WP rank-and-file, and quite a number of the party's ardent supporters, for a more robust opposition to the PAP.
"As head of the WP, Mr Low has generally been relatively taciturn, which has not necessarily been a bad thing especially after the disastrous state of opposition politics following the 1997 general election.
"But that approach, together with running a tight ship, is slowly being overtaken by other developments," he added. â€¨- THE STRAITS TIMES