"The UPA government must convene a special session of the Parliament to prove its majority on the floor of the House after withdrawal of support to it by the TMC," he said on the sidelines of a function here.
Sangma, once a TMC leader himself, lauded West Bengal Chief Minister Mamata Banerjee for taking a "bold step" by severing ties with UPA government over differences on the issues like FDI in retail, diesel price hike and other economic policies.
"She has taken a bold step to sever ties with the UPA government," Sangma said.
He also defended his failed bid in the presidential polls and said that he knew that he was unlikely to win that election, yet contested the polls for paving the way for the Schedule Tribe people as one of them will definitely become the President one day.
"The ST people will become the President of the country one day," the former presidential candidate said.