who had been a bitter critic of the Congress and Gandhi accusing them for the upliftment of Scheduled Castes?

B.R. Ambedkar

Explanation:

Bhimrao Ramji Ambedkar, the father of the Indian Constitution, was a harsh critic of Congress and its members, especially Mahatma Gandhi and Congress leaders whom he held accountable for the bad treatment that the Dalits were given in India. To B.R. Ambedkar was against the patronizing approach of Mahatma Gandhi toward the Dalits. He even wrote the book to openly criticize them in 1945. The reservation od the Schedule caste and scheduled tribe in the elections was the fruit of his hard work.

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explanation:

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