Bayron Biswas, the Left-supported Congress candidate who won the recentSagardighi by-poll, was sworn in as a lawmaker on Wednesday.

After Speaker Biman Banerjee administered the oath of office to Biswas, the first-time legislator became the sole Congress MLA of the Bengal Assembly.

Biswas was accompanied by two former lawmakers of his party, Nepal Mahato and Asit Mitra.

Minister Sandhyarani Tudu was present on behalf of the treasury benches, while three BJP MLAs — Bankim Ghosh, Ambika Roy and Satyen Roy — were also present in the House.

The three BJP lawmakers welcomed Biswas to the Assembly with a bouquet of flowers as a gesture of political courtesy.

The Sagardighi by-polls —necessitated by the untimely death of Trinamul’s three-time MLA Subrata Saha in December 2022 — were held on February 27. Its results were declared on March 2.

Biswas’s oath of office was administered 20 days after he was announced as the winner.

Earlier, he had visited the House to meet Speaker Banerjee during the Budget session and asked him about the delay in his swearing-in.

Sources said that Biswaswas told that a letter from the parliamentary affairs minister had already been sent to Raj Bhawan and once the governor’s assent was received, his oath would be administered.

Governor C.V. Ananda Bose wrote to the Assembly on Monday, authorising Speaker Banerjee to administer Biswas’s oath of office.

Even as Biswas was being sworn in, Trinamul Congress state secretary Kunal Ghosh demanded his arrest for allegedly abusing a ruling party member.

Biswas allegedly verbally intimidated Sanjay Jain, a Trinamul worker from Dhulian. An FIR was lodged against Biswas. Trinamul leaders led by MLA Amirul Haque had gheraoed Sagardighi police station on Monday.

Police have begun a probe into the complaint.

“He (Biswas) abused the women of Sanjay’s family. He should have been arrested before he was sworn in. Adhir Ranjan Chowdhury (state Congress unit chief ) must clarify if he stands by what Bayron (Biswas) said or not,” Ghosh said.

On the charges, Biswas said: “The court will decide.”