Parliamentary Affairs Minister M. Venkaiah Naidu on Sunday said the Congress was stalling the nation's progress instead of playing a constructive role as an opposition party."Now people are feeling that while in power, they (Congress) neglected development and while in opposition they are obstructing (economic) growth," Naidu told reporters here."While in power, they pushed India backward, now in opposition they don't want India to move forward," Naidu said.According to him, the Congress and its allies were perturbed over the increasing popularity of the Narendra Modi government.Naidu also said that passing the Goods and Services Tax (GST) bill in parliament was important as it would convert the country into one single market.He said almost all the states and political parties were in favour of the GST bill and most issues have been ironed out.Stopping the GST bill will hurt national interests, he added.Citing's credit rating agency Moody's warning that any delay in economic reforms would threaten economic growth, Naidu said the statement should be taken seriously.