Himpunan Hijau activist Wong Tack came close to defeating MCA president Liow Tiong Lai in the last general election, losing the Bentong parliamentary seat by only 379 votes.
While Wong has continued to work the ground in Bentong, the activist who contested under DAP's banner may not get a second shot if he is found guilty of rioting.
Wong, in a statement, said his more than three years trial, along with 14 others, was at its tail end as a directive had been given to "conclude the case as soon as possible".
Wong and 14 others were on June 22, 2014 charged with rioting under Section 147 of the Penal Code and illegal assembly under Section 145 of the same law for their protest outside the Lynas Advance Material Plant (Lamp) in Gebeng, Pahang.
Both offences carry a punishment of up to two years imprisonment or a fine or both.
Under the law, someone who has been jailed for a year or fined RM2,000 is barred from contesting the election for five years.
"The trial will continue on Feb 27 and 28. I will take the witness stand on the second day.
"Let's continue to march forward and fight on, hidup hijau," said Wong.
The Himpunan Hijau was a green movement which was formed in response amid concerns with the Lynas plant which processes rare earth.
Lynas had stressed the plant was safe and any radiation produced was within the permissible level.
The movement received strong support from the opposition.
In the 2013 general election, Wong contested under DAP's banner in Bentong against Liow, who was at that time the MCA deputy president.
Liow garnered 25,947 votes to Wong's 25,568 votes.