14 parties opposed to the BJP took part in the meeting.
As the leaders of 14 opposition parties met in Patna on Friday to chalk out a strategy for next year's Lok Sabha polls, top BJP leaders played down the meeting, with Home Minister Amit Shah calling it a mere "photo opportunity".
Bharatiya Janata Party (BJP) chief J P Nadda said the leaders who attended the meet were those who were jailed by the Congress during Emergency, while Union minister Smriti Irani said the Congress is rallying opposition parties as it is unable to win elections on its own.
Addressing a rally in Jammu, Mr Shah said opposition unity is "nearly impossible".
He also slammed former Congress chief Rahul Gandhi, saying he has the habit of criticising everything.
"A photo session is happening in Patna. All the opposition leaders have come together on a single platform to convey the message that they will challenge the BJP, the NDA and (Prime Minister Narendra) Modi (in 2024)," Mr Shah said.
"All I want to say to these opposition leaders is that your unity is nearly impossible and even if it happens, irrespective of how unitedly you appear in front of people in 2024, Modi's return with more than 300 seats is confirmed," he said.
Mr Nadda, who was in Odisha's Kalahandi district, said leaders who were jailed by former prime minister Indira Gandhi during Emergency are now welcoming her grandson, Rahul Gandhi.
Addressing a public meeting in Bhawanipatna, Mr Nadda said, "Strange things are happening in politics today. Leaders jailed by Indira Gandhi have now joined hands with her grandson, Rahul Gandhi."
He pointed out that RJD chief Lalu Prasad was jailed for 22 months, while JD(U) chief Nitish Kumar was behind the bars for 20 months during Emergency.
"I saw Uddhav Thackeray reaching Patna to attend the opposition meeting. His father, 'Hindu Hriday Samrat' Balasaheb Thackeray, was opposed to the Congress all along. Balasaheb had once said he will shut the 'dukaan' (referring to his political party, Shiv Sena) rather than joining the Congress. Now, his son is closing down the 'dukaan'," Mr Nadda said.
Ms Irani, who defeated Mr Gandhi from Amethi in the 2019 Lok Sabha polls, said the Congress is seeking the support of other parties as it is "incapable of defeating Prime Minister Narendra Modi alone".
She said it is "ironic" that some of the leaders who witnessed the "murder of democracy" during Emergency have assembled under the Congress's parasol in Patna.
"I want to especially express gratitude to the Congress for openly announcing that it is incapable of defeating Modi alone. It needs support. Power has moved from the palaces to the people. That is why those who take pride in their political legacy will now have to go to those they had put behind bars during Emergency," Ms Irani said.
Top leaders of opposition parties held deliberations to chalk out a roadmap for the formation of an anti-BJP front in the 2024 Lok Sabha polls. The meeting was hosted by Bihar Chief Minister Nitish Kumar and his deputy Tejashwi Yadav.
Altogether, 14 parties opposed to the BJP took part in the meeting.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)