The three leaders formally joined the BJP at the party's state headquarters in Kolkata's Salt Lake in the presence of Bhattacharya, who maintained that the BJP had consistently welcomed only those TMC leaders who had not been associated with corruption.

"The BJP has always wanted those who remained in the Trinamool but were not involved in corruption to stand with us," Bhattacharya said.

Rajya Sabha speculation intensifies

The development came a day after the Election Commission issued the notification for elections to three Rajya Sabha seats from West Bengal, triggering speculation that the BJP could nominate the newly inducted leaders to the Upper House.

Bhattacharya declined to confirm or deny the possibility, saying only: "Let the discussions continue."

Political observers have linked the timing of the induction with the upcoming Rajya Sabha election, although the BJP has made no official announcement regarding its candidates.

'Exception, not a policy shift'

After assuming charge as the West Bengal BJP president, Bhattacharya had stated that the party would not admit Trinamool leaders into its ranks.

His subsequent remarks, suggesting that the BJP's doors could remain open for "good" Trinamool leaders, had sparked political debate and criticism, including within his own party.

On Thursday, Bhattacharya reiterated that the BJP's broader position remained unchanged.

"Earlier, I had said the doors were closed for Trinamool leaders and workers. I still stand by that. Today's induction is an exceptional event, not a deviation."

Referring to the English proverb, "The exception proves the rule," Bhattacharya added, "Those in the Trinamool who have not been involved in corruption, have not oppressed people, have not sold government jobs and have not deprived citizens of their rights—we had already appealed to them to come forward and help remove the Trinamool. They have responded to our call."

"We had already wanted such people to stand with us. Therefore, there is no issue in welcoming them into the party," Bhattacharya said.

Former TMC Rajya Sabha MP Sushmita Dev asserted that no one could accuse her of involvement in corruption during her political career.

"No one can say that I was associated with corruption. I realised only after joining the Trinamool that corruption on such an unbelievable scale could exist. My critics may point to many negative aspects about me, but no one can say I was involved in corruption."

Sukhendu Sekhar Roy also criticised the Trinamool over corruption allegations during the joining programme.

Responding to questions about their political past, Samik Bhattacharya said: "Everyone has a past. Their only identity now is that they are BJP workers."

Following the Bengal Assembly polls, the BJP had constituted a three-member committee to scrutinise applications from leaders seeking to join the party from the Trinamool Congress.

The party had also indicated that disciplinary action could be taken against leaders who admitted defectors without approval.

Bhattacharya's earlier remarks about accommodating "good" Trinamool leaders had triggered controversy.

Former West Bengal BJP president and Union minister Dilip Ghosh had publicly disagreed with the statement.

Bhattacharya later clarified that he had never claimed there was such a thing as a "good Trinamool".

He had instead argued that leaders who helped build the Trinamool during difficult times but neither benefited from power nor engaged in corruption could be considered for induction at an appropriate time.

On Thursday, he reiterated that position by saying the BJP had already invited corruption-free Trinamool leaders to join the party.

Political journey of the 3 leaders

Sukhendu Sekhar Roy had criticised the former Trinamool-led state government after the change in political equations and resigned both as a Rajya Sabha MP and from the Trinamool Congress.

Earlier this year, he met Union Home Minister Amit Shah during the latter's visit to Kolkata to mark the birth anniversary of Shyama Prasad Mukherjee.

During the Assembly election campaign, Prime Minister Narendra Modi had also referred to Sukhendu's late father, Shibendu Sekhar Roy, fuelling speculation about his political future.

Thursday's induction into the BJP has now formalised that move.

After resigning from the Rajya Sabha as a Trinamool MP, Sushmita Dev, daughter of late Congress leader Santosh Mohan Dev, met Assam Chief Minister Himanta Biswa Sarma.

At the time, political circles speculated that she might return to active politics in Assam after leaving the Rajya Sabha from West Bengal.

Instead, she joined the BJP in Kolkata.

"I could have taken BJP's digital membership from home. But the leadership decides where one formally joins. They asked me to come here after Shamik da invited me," she said.

"I live in Assam, and I have met the Assam Chief Minister. He also told me that I should show respect to the people of Bengal because Bengal sent me to the Rajya Sabha twice," Sushmita Dev said.

Asked whether she would now focus on West Bengal politics, Samik Bhattacharya said Sushmita would work for the BJP across the country.

Prakash Chik Baraik, another former Trinamool Rajya Sabha MP from Alipurduar who resigned alongside Roy and Dev, also joined the BJP on Thursday.

Sources hint at Rajya Sabha possibility

According to BJP sources, the party may consider nominating Sukhendu Sekhar Roy, Sushmita Dev and Prakash Chik Baraik to the Rajya Sabha.

The sources noted that a candidate requires the support of 147 MLAs to secure election in the current bypoll.

With the combined strength of the Opposition in the West Bengal Assembly remaining below 100 legislators, a contest appears unlikely, making the BJP's three declared candidates virtually certain of victory if nominated.