The project would have involved construction of around 280km of high-speed line and aims to shorten journey times and improve economic integration. While initially proposed in the 1990s, the project gained momentum in 2013 after being reaffirmed as a priority by various governmental bodies.

Alignment studies and environmental impact assessments have been taking place. However, there has been strong opposition, which became apparent in extensive public consultations that took place in 2024. Particular concern was expressed on the impact of construction on Île-de-France residents and the environment.

The Île-de-France regional government has echoed these concerns and has been particularly vocal in its criticism, with Valérie Pécresse, the region’s president, calling the €11bn project “economic madness”.