De Sarnez resigned after a month due to a scandal involving alleged payment for work she did not perform, but was elected a few days later to represent the 11th constituency of Paris in the National Assembly.

Marielle de Sarnez was born in the 8th arrondissement of Paris[1] on 27 March 1951 and grew up in an aristocratic family with close ties to the French political establishment.

[2] From 1961 to 1967, her Gaullist father Olivier de Sarnez, who had been in the French Resistance, was chief of staff to Roger Frey, Interior Minister, and her mother was responsible for floral arrangements at the Élysée Palace.

)[3] After earning her high school degree from Lycée La Fontaine,[5] de Sarnez began working in retail rather than continuing her studies.

[2] Initially the movement and her place in it felt modern to de Sarnez, but she grew disappointed by the rightward turn, especially the anti-abortion politics, that the new administration adopted, and wished Giscard d'Estaing had taken the opportunity to break from the right-wing UDR (predecessor to the Rally for the Republic, RPR) and form a majority government without them.

[5] In 1978, de Sarnez co-founded the Union for French Democracy (UDF), aimed at developing a center-right coalition to back Giscard d'Estaing and provide a counterweight to the Gaullist right.

[8] After the Plural Left won the 1997 legislative elections, in 1989 through 1993 de Sarnez became Secretary-General of the opposition general assembly, while Bayrou was President of UDF.

In 2002, they earned 6.84% of the first-round vote, a fourth-place finish while the neo-Gaullist right-wing (RPR) and extreme-right (National Front, FN) candidates Jacques Chirac and Jean-Marie Le Pen, respectively, advanced.

[2] The 2007 election loss nevertheless marked a significant turning point, as Bayrou announced publicly he would not vote for Sarkozy, breaking from the dominant right-wing UMP to form the centrist Democratic Movement (MoDem).

"[5] In the 2016 presidential primary held by LR, de Sarnez endorsed Alain Juppé over Sarkozy, but both lost in a surprise upset by François Fillon.

[10] Bayrou, in consultation with de Sarnez, decided not to run in the 2017 French presidential election and they both instead supported Emmanuel Macron of La République En Marche!

"[3] Devoted to the cause of a unified Europe, she began her elected career in 1999 as a member of the European Parliament (MEP) for Île-de-France, heading the UDF list in 2004 and serving until 2017.

[7][2] A member of the UDF before 2008 and MoDem after 2008, de Sarnez served as vice-chair of the Alliance of Liberals and Democrats for Europe, and sat on the European Parliament's Committee on Culture and Education.

In 2016, she served as the parliament's rapporteur on a plan to lend Tunisia €500 million on favourable terms to help it reduce its external debt and consolidate its democratic mechanisms.

[18] Both she and Bayrou (the new Minister of Justice) resigned,[2] just before the 2017 legislative election in which de Sarnez was a candidate with Emmanuel Macron's newly formed party, La République En Marche!