Congress's parliamentary strategy group chaired by Sonia Gandhi will meet on Sunday to strategise on the Citizenship (Amendment) Bill, sources said.
The party is likely to strongly oppose the bill which is expected to be tabled on Monday.
The bill seeks to grant citizenship to non-Muslims from Pakistan, Bangladesh and Afghanistan escaping religious persecution there. The bill was cleared by the Union cabinet on Wednesday.
Congress leader Rahul Gandhi had said the party will oppose the bill.