Elected councilman of La Courneuve in 1989, on a slate of the Union of the Left led by James Marson, Poux became deputy-mayor on 1 March 1995, and delegate for employment and public procurement.

[2] In 2001, Poux led the Union of the Left slate in La Courneuve, and was elected to the council in the first round, with 57.47% of votes cast.

[6] In 2005, following the shooting death of little Sid Ahmed on 19 June 2005, Poux met with the Interior Minister Nicolas Sarkozy, who announced that he wanted to "clean up the city of Kärcher".

After having first welcomed the progress due to the joint efforts of the prefecture and municipal services,[7] Poux then pronounced as unfulfilled commitments from the state.

[11] Poux initiated a local referendum, held on 7 December 2003, to allow the people of his city to have the final choice about joining the urban community Plaine Commune, which was created in 2000.

Open to foreign residents in the city, the vote was challenged by the departmental prefect, but the municipal attorney validated the decision of Courneuviens to join.

[15][16] At the end of March 2007, the French Communist Party (FCP) nominated Poux to be a candidate to succeed Muguette Jacquaint, to represent the 3rd district of Seine-Saint-Denis in the National Assembly.

In the cantonal elections in March 2011, the FCP made the township of La Courneuve the symbol of its determination to recapture[19] the General Council seat.