Pradesh Congress Committee (PCC) president Revantha Reddy claimed that once the assembly polls are over these three parties would be in a formal alliance for the Lok Sabha polls, just as the BJP and JDS did in neighbouring Karnataka. While maintaining that Congress will score a big victory in the Telangana assembly election, Reddy said at the All India Congress Committee (AICC) media briefing on Thursday that BJP, BRS and AIMIM have already worked out an informal seat-sharing formula for the Lok Sabha polls.