West Bengal Chief Minister Mamata Banerjee today hit out at Prime Minister Narendra Modi asking why he frequently compares India with Pakistan. Ms Banerjee, while addressing an anti-citizenship law rally in Siliguri, said it is a shame that even after 70 years of Independence, people have to prove their nationality. "India is a big country with a rich culture and heritage. Why does the PM regularly compare our nation with Pakistan? Are you the prime minister of India or the ambassador of Pakistan. Why do you refer to Pakistan in every issue?" the chief minister said.