Trinamool Congress, a former ally of UPA, will move a no-confidence motion against the UPA government on Thursday when Parliament meets for the winter session.
Party sources said the motion would be tabled just before the sitting on the first day of the session of the House.
Party chief Mamata Banerjee has directed all the party MPs, except Kabir Suman who is considered a rebel, to be present in the Lok Sabha on Thursday, sources said.
Trinamool Congress has 19 members in the Lok Sabha.
Strongly opposing FDI in retail sector, Banerjee has remained adament in moving the no-confidence motion despite being isolated by the opposition parties over it.
Banerjee had said on Wednesday that she has no hesitation in supporting even a no-trust motion moved by Left parties.
"If necessary, I am even prepared to go to the CPI-M state party headquarters in Alimuddin Street and talk to its secretary Biman Bose," she had told reporters in Kolkata.
DMK, the second largest party in UPA with 18 MPs, has also kept the government on tenterhooks declaring its opposition to FDI policy but it was not known how the party would vote in the event of a voting either on a no-confidence motion or a resolution under Rule 184.
Congress has said it has no problem with any no-confidence motion. The party, however, indicated its unwillingness for a debate under a rule that entails voting on any issue including FDI in retail.
The understanding in the party is that while nobody wants an election and parties will not like the government to fall, a voting during discussion could create difficulties for UPA constituent DMK and outside ally Samajwadi Party in supporting the government on FDI in multi-brand retail.
Both the parties have already expressed reservations against it and if any of them votes against FDI, it will be embarrassing for the government though this poses no threat to its survival.
Parliamentary affairs minister Kamal Nath has expressed confidence about the government's numbers maintaining that it was upto the Speaker to decide the form under which a discussion could be taken up.
"We are confident of our numbers ... We are not a government without numbers. As and when required we will establish it on the floor of the House," Nath said.