The move comes exactly two weeks after the President has appointed Mahinda Rajapaksa as new Prime minister replacing Ranil Wickremsinghe.
President sworn in ministers to the remaining cabinet posts on Friday evening before announcing the dissolution.
Parliament was to convene on Wednesday and speaker Karu Jayasurya and group led by ousted Prime minister Ranil Wickremsinghe have demanded that parliament take on vote to decide upon majority on the first day itself.
Earlier, a government spokesman said new government still needed at least eight more votes in the 225 member assembly to reach the required 113 for majority.
He said that at the moment they have 104 or 105 MPs but expressed confidence that they will prove their majority during floor test.