Member of the National Assembly

In 2012 Lemaire was returned as Deputy for one of the eleven newly created constituencies, each elected by French overseas citizens to the French National Assembly. The constituency she represented as inaugural Deputy includes all registered French citizens living in the ten countries throughout Northern Europe—Iceland, Norway, Denmark (including the Faroe Islands and Greenland), Sweden, Finland, Great Britain, and Northern Ireland, Ireland, Estonia, Latvia, and Lithuania. As of 2011, it recorded 140,731 French citizens on its electoral roll, with the vast majority (113,655) living in the United Kingdom, which has the third-largest French expat population in the world. Consequently, her election campaign received considerable attention at the time from the British press.^[8][9]

Having won 55% of the vote, during her term as Deputy she regularly appeared in the British media regarding French politics. In May 2014, upon assuming French governmental ministerial office, Lemaire resigned her parliamentary seat and was succeeded by Christophe Premat.^[10]

Secretary of State for Digital Affairs

Upon joining the Ministry for the Economy, Industry and Digital Affairs in Paris, Lemaire had been a leading proponent of net neutrality legislation.^[11]

She was involved in the French Tech movement, which unites French digital startups worldwide.

She resigned from the position in February 2017 to focus on the Socialist Party's candidate campaign for French presidential election. She then joined the campaign to retain her seat in the French Parliament but was severely defeated by Alexandre Holroyd of La République En Marche!^[12]