Prime Minister Narendra Modi on Wednesday lashed out at Congress for wearing black dresses on August 5 in protest against price rise, saying those who believe in "black magic" will never be able to win the trust of people again.

Dedicating the second-generation ethanol plant worth Rs 900 crore here, the Prime Minister also attacked certain opposition parties for engaging in politics of freebies, saying such things would only do a disservice to the nation as it hampers investment in new technology.