Selection of wrong candidate, internal feud and losing a significant portion of vote bank led to Awami League's defeat in the Habiganj-1 constituency for the first time in the last four parliamentary elections, observe locals and leaders of both AL and BNP.
Rising prices of essentials and deterioration of law and order also contributed to AL's defeat in the constituency where its late leader Dewan Farid Gazi defeated BNP candidate Sheikh Sujat Mia by a wide margin of over 72 thousand votes in the last parliamentary polls.
People are annoyed with the ruling party due to price spirals and worsening law and order, said Sakhawat Hasan Jibon, assistant organising secretary of central unit BNP.
"AL didn't groom any alternative leadership and there had been internal feuds in the party which favoured our candidate," he added.
"The ruling party also lost some of its minority votes. In a remarkable turnaround, we obtained more than 15 percent of the minority votes."
Talking to The Daily Star an AL-leaning union parishad chairman in Bahubal said AL's selection of candidate went wrong.
"We could have won the seat easily by holding memorial meetings only if Dewan Shahnewaz Gazi Milad, son of Dewan Farid Gazi or Reza Kibria, son of former finance minister Shah AMS Kibria, were nominated," he mentioned, seeking anonymity.
One of the two upazila parishad chairmen of Nabiganj and Bahubal, who is an influential local AL leader, did not work for the party candidate, sources in Habiganj AL said.
“Some of our leaders did not work for our candidate which proved suicidal,” Mujibur Rahman, president of Nabiganj upazila AL, told The Daily Star.
"There were nine candidates including myself. Once Mushfiq Hussain got the nomination I started working for him, but some of them remained inactive," noted Mujibur.
According to him price hike had been one of the major issues and obtaining lesser votes in the minority populated areas was another reason for the setback.
Results show BNP candidate did well in the tea gardens which are known as vote banks of AL.
BNP bagged more votes in one centre out of six in the tea gardens while Jatiya Party candidate won in another. The rest, however, went to AL candidate. Compared to the previous election results this was a rarity.
Locals said the tea garden workers had some unfulfilled demands which led to the swing votes.
In Thursday's by-election, Sujat secured 81,330 votes while his rival Mushfiq Hussain Chowdhury of AL bagged 80,045 votes.
Abdul Munim Chowdhury of Jatiya Party, a component of AL-led grand alliance, pulled 22,220 votes helping Sujat prevail on Mushfiq.