He said External Affairs Minister Pranab Mukherjee, who is also the convener of the UPA-Left committee on the nuclear agreement, had a telephonic discussion with him yesterday ahead of the October five meeting of the committee.
"I have told him, you (Mukherjee) are convening the meeting. You will be present there. But we cannot compromise," the CPI-M patriarch said.
The committee will have another meeting later next month, Basu said.
CPI-M general secretary Prakash Karat has submitted a report before the central committee on the issue, Basu said adding it was being discussed.
While the Politburo discussed the issue yesterday, the Central Committee began three-day deliberations today.