His career began in 1862 when he joined the firm of W. P. Gillanders, Attorneys of the Calcutta Supreme Court, as a clerk. In this post he acquired a good knowledge of law which greatly helped him in his later career.
In 1864 he was sent to England where he joined the Middle Temple with a scholarship and was called to the Bar in June 1867. On his return to Calcutta in 1868, he found a patron in Sir Charles Paul, Barrister-at-Law of the Calcutta High Court.
Another barrister, J. P. Kennedy, also greatly helped him to establish his reputation as a lawyer. Within a few years he became the most sought after barrister in the High Court. He was the first Indian to act as a Standing Counsel, in which capacity he officiated four times.
In 1883 he defended Surendranath Banerjea in the famous Contempt of Court Case against him in the Calcutta High Court. A moderate in politics, he was attracted to it early in life.
Prior to proceeding to England to study law he had helped Girish Chandra Ghosh to start the newspaper ‘Bengalee‘, for which he used to compile a summary of weekly news on an honorarium of Rs 20 a month.
He worked in this capacity for about three years. He carried on his political activities even during his student life in England where he helped in the establishment of the London Indian Society which was later amalgamated with the East India Association.
He presided over the first session of the Indian National Congress held at Bombay in 1885. In the 1886 session held at Calcutta he proposed the formation of standing committees of the Congress in each province for the better co – ordination of its work and it was on this occasion that he advocated that the Congress should confine its activities to political matters only, leaving the question of social reforms to other organisations.
An eminent lawyer, he was severe in his denunciation of the jury system as it prevailed in India since the introduction of the ‘Amendment of the Criminal Procedure Code’ by the Law member Sir James Fitz James Stephen which empowered the judges to enhance sentences on appeal.
The salt tax which much later assumed historical significance under Mahatma Gandhi was criticised by him as an unjust tax on “almost the chief necessity of life” in a poverty stricken land where people could hardly afford two meals a day.
To propagate India’s case in England a London Agency had been established in 1888 with the help of Digby. Dadabhai Naoroji, and Bonnerjee raised funds in India for its support. He advocated the establishment of a Royal Commission for the reduction of military expenditure and its’ just apportionment between England and India.
Like other nationalists of the day, he wanted industrialisation of the country and welcomed the Swadeshi Movement. He represented Calcutta University in the Bengal Legislative Council in 1894 – 95. In 1902 he went to England to settle down there on grounds of health and started practising in the Privy Council.
In England he carried on his political activities by delivering speeches on Indian affairs. He also made two unsuccessful attempts to enter Parliament. Surendranath Banerjea thought that “he was not an agitator in the ordinary sense” and believed that “his association with the (Congress) movement gave it a dignity and an air of responsibility”.
“It is the British professors who have discoursed eloquently to us on the glorious constitution of their country; it is the British merchants who have shown to us how well to deal with the commodities of our country: it is the British engineers who have annihilated distance and enabled us to come together for our deliberation from all parts of the empire; it is the British planters who have shown us how best to raise the products of our soil it is all these in other words, it is all the influence which emanate from British rule in India that have made the Congress the success it is.”
From the Presidential Address –W. C. Bonnerjee I.N.C., Session, 1892, Allahabad