After joining The Greens in 2001, she stood in the municipal elections at Villeneuve-Saint-Georges that same year. She became an opposition municipal councillor in the town in June 2004.

In 2003, she joined the electoral college of the Greens; she organised the acquisition of their national headquarters. She became spokesperson for the party in January 2005. That same year on World Water Day, she swam in the Seine in Paris with three other members of the electoral college to denounce river pollution in France and to match Jacques Chirac’s promise, when he was Mayor of Paris, to swim in the Seine.

On 16 November 2006 she was elected National Secretary of the Conseil National Inter Régional, succeeding Yann Wehrling. At the age of 31, she was the youngest-ever National Secretary of the Greens.

In the 2007 legislative elections, she was the Green Party candidate in the third district of Val-De-Marne and gained 3.55% of the vote.

In March 2008 during the municipal elections at Villeneuve-St-Georges, she came in second place on a unified ticket of the PS, the MRC, the PRG and the Greens after socialist Laurent Dutheil. The ticket earned 24.36%.

On 6 December 2008, introducing a motion synthesizing four of the six activists’ voting slips three weeks earlier, she was re-offered the post of National Secretary of the Greens with 70.99% of the votes. With Jean-Luc Benhamias, she is the only secretary to be offered a second consecutive term, Dominique Plancke having completed three terms of one year.

In 2010, she along with Monica Frassoni, Renate Künast, and Marina Silva were named by Foreign Policy magazine to its list of top global thinkers, for taking Green mainstream.

The position of Minister of Housing was offered to her in the Ayrault government of the Hollande presidency, which began in May 2012. One of her tasks was to promulgate a law on social housing. Her first effort, announced 11 September of that year, failed in October, causing embarrassment to the Prime Minister. The loi Duflot replaced the fr:Loi Scellier on 18 January 2013.

In August 2014, she voiced criticisms of the French government, particularly of President François Hollande, stating that, “…wanting to be a leftist president, he never found his social base nor his supporters. This is not a question of temperament, rather it is the result of a succession of often unexpected choices, which are sometimes inconsistent with each other.”

The loi Alur (Accès au logement et urbanisme rénové) restricted landlord-tenant relations in exchange for favourable financial treatment. It passed on 20 February 2014.

In June 2017 she was for the Green Party a candidate for Parliament. She was eliminated in the first round.