[citation needed] In 2007, he became the Chief of PKR's youth wing after the leader, Mohamad Ezam Mohd Nor, left the post in 2006,[4] and he defeated Hasmi Hashim in the 2007 election to replace him.
[5][6] In 2004 election, he contested the newly created Tangga Batu parliamentary constituency in his home state, Malacca but lost to Idris Haron.
[8] In the 2018 election, he managed to retain his Bukit Katil which had change to Hang Tuah Jaya after the 2018 re-delineation but lost the Rim seat of the Malacca State Legislative Assembly.
After five years he was acquitted on 16 May 2018 and all charges were dropped on grounds that prosecutor failed to prove the case against Shamsul beyond reasonable doubt.
In the upcoming 15th General Election, Shamsul Iskandar had expressed his interest to challenge Ahmad Zahid Hamidi for the Bagan Datuk parliamentary seat.