Saumitra Khan, the BJP candidate banished from his constituency, gave a serious jolt to the Trinamool Congress by tearing apart his former party’s support base and winning Bishnupur seat by a margin of over 75,000 votes, which surpassed his own victory margin in 2014.

After his win, however, he extended his ‘warm regards’ to the CPI-M. He said: “I am grateful to them that they voted in my favour en masse to mark their protest against the Trinamool Congress’s anarchy and atrocities.”

Mr Khan, who won as an MLA on a Congress ticket in 2011 had migrated to the Trinamool Congress in 2014 and defeated the CPI-M’s Susmita Bauri in the Lok Sabha election that year. He switched over to the BJP barely four months ahead of this year’s polls after his confidential assistant Susanta Dan was arrested by police on charges of his involvement in an illegal arms deal.

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The day Mr Saumitra Khan joined the BJP, he had issued an ‘open’ challenge against Abhishek Banerjee, the Trinamool Congress youth president, saying he would give a “befitting” reply to his former party. The confrontation saw a fierce exchange of words and even legal action against Mr Khan, and an FIR was lodged against him bringing charges of bribery.

One of his kin lodged a complaint with the Barjora police station.

The Calcutta High Court, responding to a petition by the state relating to the bribery case barred the entry of Saumitra Khan to Bankura district, which eventually restrained him from campaigning in his own constituency. While that should have been an advantage for his main rival, Trinamool minister Shyamal Santra, Sujata, Mr Khan’s wife, took the baton to campaign on his behalf.

In Bankura, veteran TMC leader Subrata Mukherjee lost to BJP’s Dr Subhas Sarkar miserably by a margin of 1,64,062 votes. In 2014, Moon Moon Sen of the Trinamool Congress had defeated nine-term CPI-M MP Basudev Acharya by 98,506 votes in the seat. Dr Sarkar, the BJP candidate, had a meagre 20.31 per cent vote share then.

Dr Sarkar said: “Its a mandate given by the public against the Trinamool Congress’s atrocities and also against their appeasement politics.”

The TMC, however, claims that an ‘unexpected’ swing of CPI-M votes to the BJP caused the debacle. The CPI-M had a 31.05 per cent vote share in 2014 against 39.1 per cent of the Trinamool Congress.