Ekattorer Ghatak-Dalal Nirmul Committee's acting President Shahriar Kabir on Tuesday said it was necessary to ensure that war criminals were not let off the hook in the event of a change in government.
"This is why we are asking for redefining the purview of presidential clemency," he said in presence of International Crimes Tribunal prosecutor Tureen Afroz, who agreed with him.
Demands for amending Article 49, which gives the president powers to forgive anyone, gained momentum after Bangladesh's top appeals court commuted Delwar Hossain Sayedee's death sentence.
Many feared the war criminals would walk free if there was a change of regime.
Although Law Minister Anisul Huq had said he would raise the issue with his Cabinet colleagues, Prime Minister Sheikh Hasina said she did not support curbing the president's powers.
Kabir said, "We are not curbing the president's power. Instead, we are raising the demand to make sure the war crimes convicts are denied the right to seek presidential mercy.
"I believe it can be done any day as the pro-liberation force has a majority in Parliament."
Prosecutor Afroz said in the past, those who opposed Bangladesh's independence flaunted the national flag on their cars once the government changed.