Trinamul on Friday stood its ground on the alleged attack on BJP national president J.P. Nadda’s convoy a day before, questioning the alleged presence of a “convict” and extra cars and bikes en route, accusing the BJP of provocation and challenging the Centre’s authority to summon the state chief secretary and director-general of police over the incident.

Trinamul leader Mamata Banerjee, who launched a belligerent counter-attack after the alleged incident on Thursday, was silent on Friday.

Trinamul fielded Dum Dum MP Saugata Roy, a party vice-president, and Serampore MP Kalyan Banerjee, part of the seven-member apex steering committee of the party, to address the media on the party’s stand.

“Mr Nadda was given a security cover...which was adequate,” said Kalyan Banerjee, referring to the Z-category protectee (Nadda), who is entitled to a bullet-proof car, escort vehicles from the state as well as CRPF personnel and personal security officers of the CRPF, among others.

“When such an escorted convoy is being taken, others cannot join it. But scores of additional cars in front and behind, besides many motorcycles were seen,” he said.

“From such an unauthorised rally accompanying the convoy, a certain (BJP leader) Rakesh Singh — he is a convict, 59 criminal cases are pending against him — opened his car door and kept making lewd, offensive gestures at Trinamul supporters gathered near a party event’s dais,” the Serampore MP added.

“The question is why Mr Nadda was going along with such a convict... who kept doing such offensive things while accompanying his convoy? Why was there such provocation? Nadda himself broke the law,” he said.

The Serampore MP said three cases were being pursued by the police over Thursday’s incident, one of them against Singh. He said seven persons had already been arrested.

“Every meeting, every rally, every political programme of the BJP now has outsider goons, criminals, anti-social elements, with illegal firearms,” he alleged.

Dum Dum MP Roy said it was the BJP’s diversionary ploy to take away attention from the “the positive narrative, a development-oriented discourse” his party had been trying to focus on in the run-up to the state polls.

Later in the day, the party issued a statement on Twitter in response to alleged acts of vandalism on Banga Bhavan in Delhi and Trinamul heir-apparent Abhishek Banerjee’s residence in the national capital. “By vandalizing the Banga Bhawan in Delhi, @BJP4India has once again proven that violence is their only solution to undermine the 10 years of good work by @MamataOfficial!” it posted on the microblogging site. “This attack showcases BJP’s sheer disregard for the cultural sentiment of the people of West Bengal!” it added.

Serampore MP Banerjee, who is also a lawyer by profession, questioned the Centre over its summons to chief secretary Alapan Bandyopadhyay and director-general of state police Virendra in the wake of the incident.

“No central government official has the jurisdiction to issue such summons to the chief secretary and the director-general of police for something like this. They want to discuss the law and order situation? According to the Constitution, it is a state subject. If it is on law and order, these officials and the state government are answerable to the state Assembly. Not anybody else,” he said.

Banerjee also added that the letter from the Centre was “not only illegal but unconstitutional”.

The party’s top-tier leaders such as state ministers Subrata Mukherjee and Firhad Hakim also reacted to attacks from the saffron camp.