A by-poll is also being held for the Galsi assembly seat in Burdwan district.

According to Election Commission officials, around 45 percent polling was recorded till 11 a.m. in the constituencies spread over four districts - Howrah, Hooghly, Birbhum and Burdwan.

The poling percentages were: Bolpur 49.68 percent, Birbhum 47.7 percent, Bardhaman Purba 49.51 percent, Bardhaman Durgapur 47.07 percent, Howrah 40.16 percent, Uluberia 39.72 percent, Hooghly 43.5 percent, Serampore 40.60 percent and Arambagh 46.51 percent.

Over 1.39 crore voters are eligible choose their representatives at 17,332 polling stations in the third phase of parliamentary polls in the state.

As many as 87 candidates are in the fray in the Lok Sabha constituencies and four in the Galsi assembly constituency.

The Trinamool Congress, CPI-M, Congress and the BJP are contesting all the parliamentary seats in Wednesday's polls.

CPI-M candidate from Bolpur Ramchandra Dome alleged that "miscreants patronised by the Trinamool were preventing voters from expressing their democratic rights".

In Burdwan, a voter who was reportedly warned not to come out and vote was thrashed in public glare after he exercised his franchise, said CPI-M's Bardhaman Durgapur candidate Saidul Haque.

Congress candidate from Sreerampore Abdul Manna sat on a demonstration alleging malpractices by the Trinamool.

"Despite repeated complaints to the EC, no step has been taken. Trinamool workers have driven out all other polling agents from booths and are casting votes in favour of their candidate," said Mannan.

The Hooghly constituency includes Singur - synonymous to Trinamool's save farmland movement which catapulted it to power in 2011 by ending the Left's 34-year uninterrupted rule - which still hogs the limelight.

Also in focus are the twin seats of Birbhum and Bolpur, which have come under the scanner of the Election Commission following complaints by the opposition parties of Trinamool's high-handedness in the region led by its controversial district chief Anubrata Mondal.

The BJP has fielded celebrities like Bollywood music composer Bappi Lahiri (Sreerampore), Bengali actor George Baker (Howrah) and eminent journalist Chandan Mitra from Hooghly.

Film actor and sitting Trinamool MP Satabdi Roy is seeking re-election from Birbhum, while in Howrah, the party has nominated former India football captain Prasun Banerjee.

Former union minister Sultan Ahmed of Trinamool is seeking to retain the Uluberia seat

In 2009, Trinamool had won five, and the Left Front spearheaded by CPI-M won four of the seats which vote Wednesday.

Polling has been completed in 10 of the total 42 Lok Sabha constituencies in the first two phases April 17 and 24.

The final two phases of polling in the state will take place May 7 (six seats) and May 12 (17 constituencies). The results will be declared May 16.