Hashim graduated from Burdwan Raj College in 1928 and earned a law degree in 1931. Then he started his law practice at the court of Burwan. He took part in the election to the Bengal Legislative Council in 1936, and participated in the All India Muslim League conference At Allahabad in 1938. He also participated in Muslim League’s Lahore conference in 1940 and became the General Secretary of the party in 1944. He maintained a political proximity with Huseyn Shaheed Suhrawardy. Through Hashim's leadership, the success of the Muslim League came through in the 1946 election. He also participated in the United Bengal Movement in 1947, a movement which was opposed by his party. After the partition of India, Hashim became the parliamentary leader of the opposition in West Bengal Provincial Assembly. In 1950, he moved to East Bengal and settled in Dhaka.

In 1940, Hashim began to experience problems with his eyesight, and his condition worsened in 1950 when he became completely blind. Despite this problem, he continued his work in politics, and in 1960, he became the Director of the Islamic Academy.

Abul Hashim played an important role during the Language Movement. Because he was unable to help the movement from his party, he built a new political party named Khilafat-i-Rabbani, and was its president until 1956.

Abul Hashim wrote several books in English and Bangla. Some of his works are:

• As I see it
• Let us go to War
• In Retrospection
• The Creed of Islam