Kolkata, Oct 3 : Early trends coming in showed that the Trinamool Congress was leading in all the three constituencies, including Bhabanipur where Chief Minister Mamata Banerjee, who had lost the Assembly polls from Nandigram earlier this year, is up against BJP's Priyanka Tibrewal and CPI(M)'s Srijib Biswas. Mamata will have to get elected to the Assembly to retain the Chief Minister's chair. According to initial reports Mamata Banerjee was leading by a margin of 2,800 votes after the completion of the counting of the postal ballots. In two other constituencies -- Jangipur and Samserganj -- both in Murshidabad district, the Trinamool Congress candidates have maintained their lead. Jakir Hossain, who is contesting from Jangipur Assembly constituency was also leading by a margin of 1,300 votes after the first round of counting. Trinamool Congress candidate from Samserganj, Amirul Islam was also leading. Speaking to the media, state Transport Minister Firhad Hakim, who was in charge of the Bhabanipur Assembly constituency, told the media that the chief minister is going to win by a margin of 70,000 to 80,000 votes. "She will win by a record margin," Hakim said. On the other hand, BJP candidate Priyanka Tibrewal said, "The people have given their votes and now if everything continues in a fair way then there is no doubt I am going to win". The CPI(M) candidate pitted against Banerjee, Srijib Biswas said, "Election results don't make any difference to us. We don't do politics for a day. We stay with the people all the year round". Tight security arrangements have been made in all the counting centres of the state. Altogether 24 companies of the central forces have been deployed at the counting centres, and the entire area put under CCTV surveillance. Officials have only been allowed pen and paper and only the returning officer and observer are allowed to use phones, officials informed. Eight CCTV cameras have been fitted at the EVM strong room and the results will be declared after 21 rounds of counting. Prohibitory orders under Section 144 CrPC have been imposed within 200-metre radius of the counting centres at all three constituencies that went to the polls on September 30. Candidates and their agents, who have received both the doses of Covid-19 vaccine or have tested negative for the infection, will be allowed to enter the counting venues, the Election Commission official said. All officials and agents have been asked to abide by Covid-19 protocols, he said. Over 57 per cent polling was registered in Bhabanipur. A high voting rate at 79.92 per cent and 77.63 per cent was recorded in Samserganj and Jangipur, respectively. /IANS