Putting the onus on the UPA to ensure smooth functioning of Parliament during Budget session, he said the arrest of former Telecom Minister A Raja and findings of Justice Shivraj V Patil committee has "reinforced" the demand for a JPC.
The CPI(M) Polit Bureau member also said the Left want the JPC to investigate all deals from 1998, when the NDA government came up with a telecom policy, a stand which could lead to the collapse of opposition`s unity -- witnessed during the Winter session of the Parliament -- on the issue.
"Even without a discussion, you can give JPC. But if they insist they want a discussion (prior to the setting up of JPC), then give us a commitment that there will be a JPC, we are prepared for that (discussion in Parliament)," Yechury told Karan Thapar in CNN-IBN`s Devil`s Advocate programme.
Asked whether he was speaking on behalf of all the four Left parties, he said he believed so though there was no formal discussion among the four parties. "This is the indication I got from our earlier meetings," he said.
He was responding to reports that the government was contemplating a discussion in Parliament on a resolution for constituting JPC. Congress spokesperson Jayanti Natarajan has earlier said they were open to discussing such a resolution in Parliament on the JPC issue.
The remarks came ahead of Tuesday`s meeting with Opposition parties convened by the government to ensure that there is no washout of the Budget session.
"Let us see, if they come up with a concrete suggestion on behalf of the government in the February eight meeting, I am sure we will all positively react," Yechury said, adding that he hoped that the government will come up with some proposal to "meet both the ends".
"If the government is saying there is no JPC, then the government is disrupting Parliament," he said.
Emphasising that it was "very agonising" and they "do not welcome the disruption" of Parliament, he said his party did not want the House to be disrupted and all issues, including price rise and Hindutva terrorism, should be discussed.
Asked whether it meant that Parliament would not function if there is no JPC, he said, "Unfortunately, that`s the truth...even if I stand up and say that I want to discuss issues, if principal opposition BJP and others says first concede JPC (then there will be disruption)."
"I would not like to (disrupt Parliament proceedings).
But it entirely depends upon the government," he said.