While the TMC denied involvement in the assault, the opposition called it a display of the "state of emergency" in Bengal and the BJP workers staged protests.

Meanwhile, Deputy Election Commissioner Sudip Jain has sought a report from the state chief electoral officer on the incident.

The assault took place outside the Ghiyaghat Islampur Primary School booth under the Pipulkhola police station of the Nadia district. Majumdar, state BJP Vice-President, had gone there on receiving reports of electoral malpractice.

He found eight outsiders in a room purportedly preparing meals for polling officials. But the officials denied any knowledge of food being cooked for them, only 10 metres from the booth.

Majumdar removed the 'outsiders' and lodged a complaint with the district administration. But as soon as he came out of the booth, around 50 people surrounded him, protested and started slapping and punching him, and pushed him into nearby bushes. As Majumdar tried to come out, a protesters kicked him hard, sending him hurtling down further into the bushes in the full glare of television cameras and the presence of central forces.

The security personnel rescued him and unleashed a baton-charge to drive away the protesters. "They got enraged as I exposed their conspiracy to capture the booth. I have got injuries on arm and back," he said.

An enraged BJP filed FIRs against the TMC workers as well as the Sub-Divisional Officer for failing to protect the candidate. They also moved the Election Commission, seeking immediate intervention in the constituency.

BJP workers later hit the streets, put road blockades in the city as well as the district.

Terming it an "attempt to murder", state BJP chief Dilip Ghosh said said, "Democracy has ceased to exist in Bengal".

BJP national executive member Mukul Roy demanded removal and arrest of the district magistrate and the police superintendent. "In my entire political career, I have never seen a poll candidate being so mercilessly thrashed," he said.

"The DM is the ex-officio district returning officer, and the SP the custodian of the law in the district. But they miserable failed to uphold law and order. They should be immediately arrested and removed from their post," said Roy, who also spoke to the deputy election commissioner on the incident.

However, the TMC termed the incident a result of BJP's factionalism or "orchestrated" by Majumdar to garner sympathy. "The ground has slipped from under his feet. He knew he will lose. So he orchestrated the attack," said Rajib Banerjee, a TMC Minister.

He could be the victim of the BJP's factional feuds, he said and added, a section of the BJP leaders were not happy over his candidature.