Having made his mark in opposition during the last days of the empire, he was appointed deputy-mayor of Paris after the government was overthrown.

He was president of the chamber from 1881 — replacing Léon Gambetta — to March 1885, when he became prime minister upon the resignation of Jules Ferry; but he resigned when, after the general elections of that year, he only just obtained a majority for the vote of credit for the Tonkin expedition.

[2] Following the 1898 French legislative election, whilst the country was violently excited over the Dreyfus affair, the incumbent Premier, Jules Méline, lost the confidence of the Chamber of Deputies - subsequently allowing Brisson be re-appointed as Premier and form a new cabinet in June 1898.

[3][4] Brisson's firmness and honesty increased popular respect for him, but a chance vote on a matter of especial excitement[clarification needed] overthrew his ministry in October.

As a leader of the radicals he actively supported the ministries of Waldeck-Rousseau and Combes, especially concerning the laws on the religious orders and the separation of church and state.