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The suspension will remain as the MPs "haven't expressed remorse", Mr Naidu said. "Suspended MPs have not expressed remorse. I am not considering the appeal of Leader of Opposition (the Congress' Mallikarjun Kharge). Suspension will not be revoked," he said.
Minutes earlier Mr Kharge argued the government's move to suspend the MPs (the list includes six from the Congress) was "selective" and against the rules. "I request you to revoke suspension of 12 opposition MPs... have been suspended selectively," he said.
"Every Member should be allowed to make a Point of Order... Rule says Chairman has to take name of MP first and then a Question has to be made prior to suspension. Then a Motion for Suspension can be moved. This has to be on the day of the incident. In the present case, none of the MPs were named before the motion," he explained.
Mr Naidu countered, saying: "In the bulletin all their names are there..." and "This is not the way. You ransacked the House and now you are teaching me a lesson. I cannot revoke the suspension of the members." He acknowledged parties' right to walk out, but said functioning of Parliament could not be affected.
The Rajya Sabha Chairman also shut down complaints about the lack of precedent for punishment of MPs for actions in a previous session. Rule 256 says a MP can be suspended "for a period not exceeding the remainder of the session".
After Mr Naidu said the suspension stood, the opposition, joined by the Trinamool Congress, walked out. The Rajya Sabha was adjourned till 2 pm, but continuing interruption after its resumption lead to the House being closed for the day.
There were protests in the Lok Sabha too, where the Congress lead another walkout; the party's leader in the Lower House, Adhir Ranjan Chowdhury, said it was to show support for the 12 suspended MPs. He accused the government of using suspension as a "threat" to silence the opposition. The Lok Sabha was also briefly adjourned, after which Speaker Om Birla spoke to opposition party leaders and brokered a truce.
Opposition MPs from both Houses staged a protest at the Gandhi statue, after which floor leaders met in Mr Kharge's chambers. They have been supported by the Trinamool, for whom MP Nadimul Haque told ANI: "We are standing with the Opposition... but will take our own path". The Trinamool - making a run at the BJP in the 2024 election - had distanced itself from a joint opposition statement.
Earlier 16 parties - not including the Trinamool - met Mr Naidu. They said that if the suspension is not revoked, they intend to boycott today's Rajya Sabha session. The 16 included the Congress, the DMK, the Shiv Sena and NCP, the CPM and CPI, the RJD, J&K's National Conference, the Telangana Rashtra Samiti, and the Aam Aadmi Party.
Yesterday, 12 MPs, including the Shiv Sena's Priyanka Chaturvedi, were suspended. The opposition called it "unwarranted and undemocratic". This morning Parliamentary Affairs Minister Pralhad Joshi said the government had been "forced" to suspend the MPs, but was ready to consider revoking the suspension if they apologised.
With input from ANI, PTI