According to a March 31 poll by Headlines Today television, Banerjee and the parties that back him are expected to win 182 of the 294 seats in the assembly. Experts say that Scheduled Caste and tribal voters are main key constituencies that will determine the outcome.
Voting was held in 54 ridings today amid tight police and military controls to pre-empt possible disruptions.
Banerjee, from the All India Trinamool Congress, which is in power in New Delhi but in the opposition in West Bengal, has accused the leftwing administration of presiding over the economic decline of the state, which has a population of 91 million.
West Bengal ranks third among Indian states for the number of poor. In fact, poverty is widespread.
In the 2006 elections, the ruling Left Front won three quarters of the 294 seats. This time however, the government is facing accusations that it penalised farmers in favour of big business by using laws dating from the time of the British Raj to expropriate land.
State officials have argued in their defence that land was expropriated to boost the economy and increase employment.
For their part, farmers have complained that the compensation they received for the land and homes they lost fell far below their value and that in losing their land they lost their livelihood.
In 2006 and 2007, the construction of a car plant by Tata Motors in Singur, Hooghly District, and a chemical plant in Nandigram, Midnapore East led to riots in which many people were killed or injured. According to some, Communist militias were used to beat up farmers and throw them off their land.
Following the unrest, outside investment dried up in 2009, dropping by 91 per cent over the previous year.
Unemployment, especially among urban youth, has instead been high, and has become another major issue in this campaign. At 13 per cent, it is double what it is in Rajasthan, Uttar Pradesh and Karnataka.
The Left Front, which is led by outgoing Chief Minister Buddhadeb Bhattacharjee, blames New Delhi for the situation, arguing that inflation and rising prices are due to the federal policies. At the same time, the ruling coalition accuses the federal government of corruption and mismanagement.
Times have changed since 1977, when the newly elected Communist Party carried out land reform, which gave land to 1.5 million farmers, and imposed state controls over industry.
Ten years ago, the state government in Kolkata, having seen states like Haryana and Andhra Pradesh grow economically twice as fast as West Bengal, announced tax breaks to lure companies to new trade zones. However, this came with land expropriations that were carried out without concern for their impact.
State elections will be held in six phases, the last one on 10 May. Results should be announced on 13 May.