The MPs, including senior party leader K Keshav Rao, decided not to attend the session and were closeted at his residence.
Karimnagar MP Ponnam Prabhakar said the Telangana Congress MPs who have resigned their posts will not attend the session.
"We want a separate Telangana state. That is our only demand. So, we are not attending Parliament," he said.
While 9 MPs are from Lok Sabha, Rao is from Rajya Sabha. Congress has 12 MPs in Lok Sabha from the Telangana region.
The lawmakers are scheduled to meet Congress General Secretary in-charge of Andhra Pradesh Ghulam Nabi Azad in the evening and hold further consultations.
The MPs resigned on July 4 in protest against the Centre's delay in announcing the formation of a Telangana state, but Lok Sabha Speaker Meira Kumar and Rajya Sabha Chairman Hamid Ansari have not yet taken any decision on them.