[4] The incumbent All India Trinamool Congress government led by Mamata Banerjee won the election by a landslide, despite opinion polls generally predicting a close race against the Bharatiya Janata Party, which became the official opposition with 77 seats.

[11] According to various political analysts, the shifting of the Left Front and other opposition voters towards the BJP caused the party's vote share to significantly increase.

[12][13] In spite of widespread violence, the BJP emerged as the second largest party in the 2018 elections to the state panchayats mainly due to the shifting of the Left Front's voter base.

Public anger towards corruption and hooliganism of a section of TMC cadres in rural areas during the 2018 panchayat elections, religious polarisation by BJP fueled by resentment of a section of Bengali Hindu society towards Mamata Banerjee's tactics of Muslim appeasement,[17] and large scale support of the Rajbongshi and Matua communities for granting Indian citizenship to exclusively non-Muslim Bangladeshi immigrants[18] over fears of a demographic change fuelled by infiltration of undocumented Muslim immigrants from Bangladesh, allegedly supported by Mamata Banerjee have been cited as important reasons behind the rise of BJP in West Bengal alongside the decline of Left Front.

With Narendra Modi becoming the only non-Congress prime minister to remain in power for two consecutive terms (amounting to ten years) without depending on the support of the National Democratic Alliance, and the BJP fulfilling the wish of its founder Shyamaprasad Mukherjee[c] by revoking the special status of Jammu and Kashmir[19] and long standing promise of resolving the Ayodhya dispute in favour of Hindus, the party considered the formation of a BJP-led state government in West Bengal (a state which has historically never voted for right-wing parties in large numbers) for the first time as a means of paying homage to Mukherjee, who hailed from there.

A BJP victory in West Bengal would have also demoralised Mamata Banerjee's attempts of creating a non-BJP non-Congress alliance of regional parties that might play an important role in the upcoming general elections.

[45][46] In 2019, the BJP-led Union Government passed the CAA in Parliament, promising citizenship to immigrants and refugees belonging to religious minorities in Bangladesh, and providing them with rehabilitation.

[51][52] Although previously mobilized by Left governments against elites under the "class" narrative, the Dalits of West Bengal began to assert their identity politically.

[56][57][58] Dissatisfaction and defection of many TMC leaders to BJP, allegedly due to rising influence of Abhishek Banerjee and Kishor in party administration was also likely to impact the elections.

[59] An event was organised by the Ministry of Cultural Affairs in Kolkata's Victoria Memorial to commemorate Netaji Subhas Chandra Bose's 125th birth anniversary, which was attended by PM Narendra Modi and CM Mamata Banerjee among others.

[60][61] Just as Banerjee got up to speak, BJP supporters started chanting "Jai Shri Ram" which prompted the CM to abandon her speech.

[95][96] Left Front chairman Biman Bose announced the candidates for the first and second-phase elections on 5 March alongside INC and ISF leaders, leaving seats for them in the list.

[193] On 22 April 2021, before the seventh and eighth phases of voting, the ECI forbade roadshows, and added that at most 500 people were allowed in public meetings.

[195] After several instances of violence, threats, and murders before the polls were announced, the ECI and the Home Ministry ordered twelve companies of Central Armed Police Forces (CAPF) to be deployed in West Bengal on 20 February.

[316][317] On the eve of polling in Nandigram, the ECI ordered the transfer of the sub-divisional police officer of Haldia and the circle inspector of Mahishadal in Purba Medinipur district to non-election assignments[318] and imposed Section 144 in that constituency.

[306][1][307][308] Mamata banerjee continued to claim that she won Nandigram, Security was beefed up in the vicinity of the Haldia counting centre amid fears of unrest.

Mamata Banerjee alleged that the returning officer of Nandigram constituency was threatened and the two observers sitting inside the counting centre were very biased.

[323][324][325] The ECI wrote a letter to the West Bengal chief secretary and directed them to take all appropriate measures to keep a strict watch and regularly monitor the security provided to the returning officer in Nandigram.

"City prostitutes"), referring to actresses Payel Sarkar, Tanushree Chakraborty and Srabanti Chatterjee, who were seen in a boat ride with TMC leader Madan Mitra in the past.

[406][407] TMC candidate Kajal Sinha from Khardaha died from COVID-19 after polling but before the results of the state assembly elections were announced, in which he emerged victorious.

[415][416] BJP MPs Subhash Sarkar from Bankura, John Barla from Alipurduar, Nisith Pramanik from Coochbehar, and Shantanu Thakur from Bangaon were made ministers-of-state in the Union Caninet after the polls.

[417] Incumbent Cabinet ministers from the state, Babul Supriyo from Asansol and Debasree Chaudhuri from Raiganj, resigned from their positions due to their failure in rallying the voters from their respective constituencies to vote for BJP.

All-India president of Congress's women's wing and its national spokesperson and former Silchar MP Sushmita Dev joined TMC,[434] and was followed by Luizinho Faleiro.

[77] AITC MLA Sovandeb Chattopadhyay from Bhabanipur resigned after the election to allow Mamata Banerjee to contest a by-election in the constituency.

Central forces were accused of kicking TMC leader Habibur Rahman, the outgoing councilor of Ward 20 of Dhulian Municipality under Samserganj Assembly.

[465][466] Priyanka Tibrewal, BJP candidate of Bhabanipur, was accused of violating the ECI's model code of conduct by travelling across the area with many cars and people at once.

[485] On the last day of the Dinhata by-election campaign, Dilip Ghosh and Sukanta Majumdar met the deputy inspector general of police, Shailendra Kumar Singh, at the Border Security Force sector headquarters of Sonari in Cooch Behar.

This was controversial because the Chief Minister could not even hold administrative meetings with Cooch Behar district officials, as the model code of conduct was in effect.

[492][493] In Kharadha, the central forces prevented TMC candidate Sovandeb Chattopadhyay from entering a booth, who alleged that they unfairly demanded to see double vaccination certificates from voters.

[497] Joy Saha's personal security guards baton charged TMC activists, injuring the Sinha's son in the process.