[1] A member of the Union of Democrats and Independents (UDI), he also served as Mayor of Douzy from 1995 to 2014.

[2] From 2005 until 2007, Warsmann served as vice-president of the National Assembly, under the leadership of president Jean-Louis Debré.

Following the 2007 French legislative election, Warsmann succeeded Philippe Houillon as chairman of the Committee on Legal Affairs.

In this capacity, he was the parliament's rapporteur on the French constitutional law of 23 July 2008.

In 2009, Warsmann introduced a bill according to which the Church of Scientology cannot be dissolved in France even if it is convicted of fraud; the change in the relevant law made the maximum penalty for fraud committed by an organisation a ban on its activities in France.