Mukul Roy was on Friday appointed the chairman of the Public Accounts Committee (PAC) in the Bengal Assembly amid protests by the BJP-led Opposition.

The Krishnagar North MLA had once been Trinamul’s de facto No 2 but switched to the BJP and who the Assembly poll. He has now returned to Trinamul without stepping down as BJP MLA.

BJP MLAs, led by the leader of the Opposition Suvendu Adhikari, walked out of the Assembly soon after Roy’s appointment was announced by Speaker Biman Banerjee.

Roy, on paper, remains a BJP MLA.

While there is no set rule on the selection of the chairman of the key standing committee, and the appointment is the Speaker’s call, the post conventionally goes to the Opposition. BJP leaders had told the Speaker they wished to nominate economist Ashok Lahiri, the Balurghat MLA.

“Nobody got a chance to discuss it. Conventionally, the PAC chairman is selected from the Opposition. Just as the government has the right to spend (funds), the Opposition has the right to examine expenses. The ruling party has broken that convention, showing its power of numbers,” Adhikari said at a news meet in the Assembly after the walkout.

“The government just tore up the relationship between the ruling party and the Opposition in the Assembly. The BJP has vowed to implement the anti-defection law in the Assembly (with regard to the likes of Roy),” said Adhikari.

The BJP has officially appealed to the Speaker to implement the anti-defection law against Roy. A hearing on the matter is scheduled on July 16. Adhikari said that if the Speaker doesn’t act soon, the BJP would move court.

Despite being a BJP member on paper, Roy’s name didn’t find mention in the list of PAC members submitted by the BJP to the Speaker. Of the 20 members who form the PAC, 14 are nominated by the ruling party, six by the Opposition. Roy’s name was proposed by Ruden Lepcha, the Kalimpong MLA of the Gorkha Janmukti Morcha’s Trinamul-backed faction and seconded by Trinamul’s Egra MLA.

Last month, during a news meet at Nabanna, chief minister Mamata Banerjee had endorsed Roy’s membership in the PAC. She also stated that Roy “is a member of the BJP”. She had said Roy had the support of the Treasury benches. However, she added that the selection of the chairman was at the Speaker’s discretion.

Adhikari said the BJP refused to chair any of the remaining standing or House committees offered to them. “In 2016, the Left and the Congress had an equal number of MLAs (77, which the BJP had at the start of this 17th Assembly) and they were asked to chair 15 such committees. We were first given nine, and later, 10 committees. We have refused the offer.”

“This is for the first time since Independence that the Opposition is not chairing the standing or House committees… Let Trinamul enjoy all the power, because this is their last term,” he claimed.

The BJP’s embarrassment with Trinamul turncoats continued on Friday, as journalists asked the party’s Bengal chief, Dilip Ghosh, in Barasat about rifts within. Ghosh said newcomers were yet to “fully fathom” the BJP. “They are facing problems. There is no problem with old-timers…” He said the BJP was mulling action against Trinamul turncoats Rajib Banerjee and Sabyasachi Dutta who had openly criticised their new party.