New Delhi, Jul 9 (IANS): The opposition BJP Monday stepped up its attack on Prime Minister Manmohan Singh and Congress President Sonia Gandhi for allegedly showing up India in a bad light internationally.

Slamming, the ruling party for a second time over the latest issue of Time magazine which calls the prime minister an "underachiever", Bharatiya Janata Party leader Ravi Shankar Prasad also demanded Singh's resignation.

"India's image has been spoiled, it is sad that a conception is being formed internationally that India is among the most corrupt nations," Prasad said.

"Sonia Gandhi cannot escape the blame, because she has given the political authority (to the prime minister) because of which the country is suffering," he said.

Asked is the opposition wanted prime minister's resignation, he said: "We have already demanded his resignation on several occasions."

"Manmohan Singh used to publicly say that you criticise me, but you never notice what the international media writes about me. Now, the world is saying what the people of the country have been saying for a long time," he said.

Time, in an upcomming cover story of its Asia edition, has dubbed Prime Minister Manmohan Singh an "underachiever" and questioned if the architect of 1991 economic reforms can rouse himself and put the country back on the high growth path.