Bangladesh virtually shuts down on poll eve: All you need to know about general elections

Hasina, who is seeking to return to power for a third consecutive time, on Saturday expressed fears that the opposition could boycott polls in the middle of voting as part of a "political trick" to evade a "humiliating defeat".

"I want to caution all about the character of (main opposition) BNP...they may say in the middle (of the elections) that we are boycotting the polls," she said.

"In that case (opposition boycott) I will ask our candidates and other contenders to continue polls until the voting is ended," Hasina, 71, said. 

The premier's comments came as the BNP is contesting the polls in a state of disarray in the absence of Zia, 73, and her fugitive son Tarique Rahman who is the acting party chief.

Zia, serving a 10-year prison term on graft charges, has been barred from contesting the polls while Rahman is living in London ostensibly to evade the law as a court has sentenced him to life imprisonment for masterminding a grenade attack on a rally in 2004 that killed 24 Awami League leaders and activists.

The BNP has stayed out of parliament since 2014 when it boycotted the last election over its demands for a poll-time non-party government.

It has returned to parliamentary politics as part of a new alliance - National Unity Front (NUF) - that was cobbled together three months ago with eminent lawyer Kamal Hossain as its convener.

Reacting to Hasina's remarks, BNP secretary general Mirza Fakhrul Islam Alamgir said "There is no dispute in our party about taking part in the polls".

"But what we see, there is no festive mood anywhere and rather a sense of fright is prevailing across the country due to government intimidation," he said. 

Bangladeshi Prime Minister Sheikh Hasina considers being called authoritarian by the western media a "badge of honour", the leader's son told Reuters on the eve of a national election on Sunday.

Hasina, who is widely expected to win a third straight term in office, has been hailed domestically for fast economic growth in the past decade and internationally for providing refuge to Rohingya Muslims fleeing persecution in neighbouring Myanmar.

But her government has been accused of suppressing dissent and jailing critics, including many supporters of the main opposition Bangladesh Nationalist Party (BNP). Many journalists say she has intimidated the media by using vaguely worded laws against them.

Hasina's son Sajeeb Wazed, however, told Reuters there was space for dissent in the Muslim-majority country of 165 million people, and that the Western media was unfair in its portrayal of his mother.

Streets in major cities including capital Dhaka wore a deserted look by late Saturday as authorities enforced a restriction on vehicle movement as part of security vigil calling out military troops "in aid of civil administration".

Army Chief General Aziz Ahmed urged voters to exercise their franchise without any fear saying more military personnel would be called out if required.

"They (military) are conducting constant patrols to ensure that nobody attempts to terrorise or cause unrest. They are also working to ensure that voters are safe," Ahmed said. 

The Election Commission last week also allowed hardline Islamist party Jamaat-e-Islami, a crucial ally of BNP, to contest the election, two months after it scrapped the fundamentalist party's registration.

BNP earlier accused the election commission of being biased during the poll campaign, a charge rejected by Chief Election Commissioner Nurul Huda.

Huda acknowledged a media report about arrests of some polling agents of BNP candidates and called such action "unwanted".

"Unless someone is wanted under certain case, police must not arrest anyone...maintain utmost neutrality in discharging your duties," he said.

"No member of law enforcement will arrest or harass polling agents of any candidate unless there are specific allegations against them," he said in a directive which he issued in a pre-poll press conference in Dhaka.

The opposition parties have alleged that thousands of their leaders and activists have been arrested to weaken them.

The CEC's comments came as BNP expressed doubts about credibility of Sunday's election alleging their supporters were intimidated and arrested while their agents too were being harassed to keep them away from polling centres..

Later BNP's Alamgir said "Now we've no expectation over the election. This election has become a complete mockery....the state, the government and the Election Commission are working together to turn it into a mockery. There's no question of win or defeat since it is not an election at all as a particular party is trying to snatch election victory by force and using the state machinery".

Alamgir, however, asked his party candidates to stay in the race until the voting ended while NUF convenor Hossain urged voters to "restore democracy" and exercise their franchise.

If all goes according to expectation, Sheikh Hasina is likely to win in a canter. The opposition is sorely missing the BNP top brass and the rest are just not good enough to take on the might of Bangabandhu's daughter. But stranger things have happened in politics. At a time when conservative politics is gradually gaining clout, Bangladesh is no exception. Hence BNP and othrer parties will hope that the voters give them a thumping mandate as they feel hard done by Hasina's crackdown.