"It seemed to me after reading the verdict that we are very unfortunate. It has made us hang our heads in shame," he said to reporters at Radisson Blu Chittagong Bay View hotel on Monday.
The Jatiya Party chief is in Chittagong to attend a programme.
"No institution remains intact now; everything is destroyed. Corruption is rampant, the fascination for power is rampant (sic)," Ershad said about the verdict.
The BNP has welcomed the verdict while the ruling Awami League, which had passed the amendment, is yet to react officially.
Speaking about the next parliamentary election, Ershad, Special Envoy to Prime Minister Sheikh Hasina, emphasised full exercise of power by the chief election commissioner to hold a fair election.
"It depends on him whether he will exercise the power and organise a fair election," the former military ruler said. "I hope he will be able to do that."
On being asked, he said, "We are the opposition, though in paper only. We are not in any alliance."
Jatiyta Party has three ministers in the government despite being the Opposition in parliament.
Ershad said the party would give its own candidates for all the parliamentary seats in the next election.
"This is our party decision. We are still firm on it. I don't know what will happen in the future," he added.