New Delhi, July 26: Mamata Banerjee today directed her party to defend Bhagwant Mann, making the Trinamul Congress the first to speak up for the Aam Aadmi Party MP who is under fire from all sides for his Parliament video.

The Bengal chief minister argued that Mann had already been punished with suspension from the Lok Sabha - Speaker Sumitra Mahajan has advised him not to attend the House till the issue is resolved - and further action would look like "political vendetta".

While the ruling BJP had demanded Mann's expulsion for "exposing Parliament security on social media", the Congress and key regional party BJD too had supported action against him.

Mamata briefed party MP Ratna De Nag, who is on the committee appointed by the Speaker to probe the "serious security implications" of Mann's act and recommend action by August 3.

"Ratna De Nag has been briefed to support Mann," Trinamul's leader in the Rajya Sabha, Derek O'Brien, said. "What was Mann's intention? It was clearly not devious. It was not to show the security of Parliament," he added.

The MP had shot a video as he walked into Parliament and uploaded it on Facebook. After the uproar, he tendered an "unconditional apology" and removed the video.

"Mann's action may be childish or immature. He has been suspended from the House and punished. Any further action would look like political vendetta," a leader quoted Mamata as saying.

AAP leader Raghav Chadha had called on her in Parliament.

The Trinamul chief asked Nag to strongly support Mann on the committee.

The panel is headed by the BJP's Kirit Somaiya, who was at the forefront of the expulsion demand. It held its first meeting today. Delhi police commissioner Alok Verma was called to give his views.

However, even the BJP now appears inclined to "go easy" and sources said the panel was expected to stop short of recommending expulsion. The sources cited "political considerations" in poll-bound Punjab.

Already hit by the resignation of MP Navjyot Singh Sidhu, the BJP does not want to "end up making a hero of Mann and boosting the AAP's growing prospects in Punjab". "We could end up further alienating the Sikhs," a Punjab BJP source said.

Mann asked today why the Prime Minister had not been suspended, and wrote to the Speaker to direct the Somaiya committee to examine Narendra Modi also for "allowing Pakistan's ISI" to inspect Pathankot air force station.

"In 2001, ISI attacked Parliament. The same ISI attacked Pathankot airbase in 2016. The PM respectfully gave the same ISI a tour of the same Pathankot airbase. The ISI took away a map of the entire airbase. Did not this endanger the entire country? Is my video a threat to national security or the PM taking the ISI on a tour of an airbase a threat to national security?" he asked.

A five-member Pakistani investigation team had entered the Pathankot airbase in March to collect evidence. They were given guided tour by the NIA. The vital installations had been covered with cloth and tarpaulin during the visit.

Government sources had another concern - if the Mann episode became a precedent, lawmakers could be sent packing for the "most frivolous" reasons.