Trinamool Congress claimed that the attack on the party's national general secretary and Diamond Harbour MP Abhishek Banerjee in Sonarpur in West Bengal was 'planned'.
The party also alleged that the BJP 'sponsored' the attack and clarified that it was not an instant expression of public anger as claimed by the BJP.
The opposition party posted photographs on its official X handle, claiming these proved the involvement of local BJP functionaries in the incident.
"If the BJP claims this attack was merely an expression of spontaneous public anger, then why was a key BJP functionary present at the scene playing such an active, directorial role? Who authorised this mobilisation?" the TMC posed in the X post.
The TMC also posted photos claiming that a woman seen in the crowd during the incident had previously been photographed alongside BJP leader Locket Chatterjee.
The party further questioned who had authorised the "mobilisation and planned the attack".
Referring to Chief Minister Suvendu Adhikari, TMC demanded his accountability for the attack on Banerjee.
Scores of people hurled stones, eggs and abuses at the Diamond Harbour MP, who escaped the mob wearing a cricket helmet and helped by aides on Saturday in Sonarpur town of South 24 Parganas district in West Bengal.
Banerjee was attacked when he went to visit the victims of post-poll violence, and later claimed that BJP activists were trying to kill him.
Unidentified people scuffled with the leader and roughed him up while raising chants of "thief, thief".
The situation quickly spiralled into chaos, with some members of the crowd reportedly attempting to physically attack Banerjee by raining blows and kicks on him, prompting swift intervention by security personnel.
"Today, I stand as a victim of political violence and state-sponsored terrorism unleashed by those who claim to be the guardians of nationalism," Banerjee wrote in a social media post.
He also thanked Congress leader Rahul Gandhi for his "concern and constant support" following the incident.
He also thanked Samajwadi Party chief Akhilesh Yadav and Jharkhand Chief Minister Hemant Soren for their condemnation of the attack.
"We stand united and resolute in our fight to protect the soul of India, defend its democratic institutions and uphold the values enshrined in our Constitution," he said.
"Last year, I travelled across five countries representing India as part of the all-party delegation for Operation Sindoor. I defended my country and stood united against terrorism," the TMC MP from Diamond Harbour said.
"This is the reality of today's BJP. If you support them, you are a patriot. If you question them, you become a target. If you stand with them, you are celebrated. If you stand against them, they try to silence you," Banerjee said in the post.
The TMC also alleged that senior BJP leaders had "weaponised" the word "Bangladeshi" as a slur for years and claimed that such remarks were now being directed at the sitting MP.
Questioning whether this was how opposition MPs were being treated under the BJP-led dispensation at the Centre, the party asked whether Lok Sabha Speaker Om Birla would condemn the incident.
It further alleged that standards of public discourse were deteriorating under the BJP rule and asserted that the attack on Abhishek Banerjee was being closely watched by people across the country and abroad.
Denouncing the attack, BJP West Bengal president Samik Bhattacharya said such incidents aren't desirable in a healthy and normal society, while insisting that his party was in no way involved.
"The BJP is not involved in such activities. But what happened could be the outcome of the anger of locals who were tortured over the years," Bhattacharya has said.
With inputs from PTI