The joint opposition walked out in protest on Sunday morning just as the all-party meeting to discuss the agenda for the Monsoon Session of Parliament started at the Parliament House complex.

The meeting hosted by Rajnath Singh, Deputy Leader of the House in Lok Sabha, saw a symbolic protest by the opposition which made its point and then returned to join the meeting.

The opposition was reacting to the presence of rebel TMC members at the meeting saying since their merger had not been formalised with the Nationalist Citizens Party of India they are still TMC constituents and cannot be invited in a separate capacity.

TMC leader Mahua Moitra, who attended the meeting, said, “Today, the entire opposition, including the Congress, Samajwadi Party, DMK, JMM, Aam Aadmi Party, National Conference, Left parties and Shiv Sena UBT, have walked out of the all-party meeting in protest. The strength of the All India Trinamool Congress in the list provided by the office is shown to be 28 members. The merger of the so-called rebel 20 MPs has not been approved by the Speaker. The 20 disqualification petitions are still pending.”

She said that after the 91st Constitution amendment, there is no room for a separate bloc. "So on what grounds did the Parliamentary Affairs Minister extend an invitation to these 20 rebel MPs and how are they attending this meeting? We have registered our strong protest and walked out as a symbol of protest. And we thank all our opposition parties for staging a walkout," she said.

Earlier, rebel bloc MP Kakoli Ghosh said all dissidents wanted development of their constituencies and this was earlier not possible.

"Earlier we were all under threat," she said.

The meeting is under way and is being attended by floor leaders of all parties.

It is being chaired by Rajnath Singh and attended by Leader of House in Rajya Sabha JP Nadda and Parliamentary Affairs Minister Kiren Rijiju.