- to ensure high-speed service of the Toulouse region through an extension of the LGV Sud Europe Atlantique and reduce the journey time between Paris and Toulouse to slightly over 3 hours.
- in a more distant and less defined future, to be part of a proposed "Southern Link", connecting the Atlantic and Mediterranean from Bordeaux to Nice via Toulouse, Montpellier and Marseille.
The project was the subject of preliminary studies between 2002 and 2004 by RFF. These proposed:
- serving Bordeaux and Toulouse through their existing central stations (Bordeaux St-Jean and Toulouse Matabiau)
- stops at Agen and Montauban, either through their existing stations, or by the creation of new stations on the high-speed line.
- a route between Agen and Toulouse following the Garonne valley and the A62 autoroute.
- three route options between Bordeaux and Agen: to the north of the Garonne valley; running along the valley; to the south, passing by Captieux. This third option, currently favoured, would permit a common first section between the LGV Bordeaux–Toulouse and the extension of the LGV Sud Europe Atlantique from Bordeaux to the Spanish border. Additionally, it would permit calling directly at Mont-de-Marsan and would offer direct access to the towns of the Pyrenees area (Pau, Lourdes, Tarbes).
Short term plans do not include a bypass of the Bordeaux area; TGVs providing the Paris-Toulouse service would go through the Bordeaux St-Jean station. The line would begin Southwest of Bordeaux at Hourcade and rejoin the existing network Northwest of Toulouse at St-Jory. The Bordeaux shunt project (Libourne-La Réole) seems somewhat incompatible with the common section option.
Line speed will be 320 km/h, enabling a journey time of 59 minutes between Bordeaux and Toulouse, and of 3:14 between Paris and Toulouse (3:07 without a stop at Bordeaux).
Service is planned to begin around 2020, for a cost of approximately 3 billion Euro.
The public inquiry into the project ended 25 November 2005. This revealed:
- a large consensus in favour of the project at Agen, Montauban and Toulouse. Among the arguments advanced were the access of Toulouse and the Garonne Valley to the high-speed network, the wish to develop rail as a less polluting transport option, and the need to respond to the saturation of Toulouse–Blagnac Airport by a transfer of air passengers towards rail. The continuation of the project up to Narbonne was also cited.
- some opposition from the southern Gironde area and particularly the Captieux region, where residents feared the destruction of natural sites and felt that the upgrading of the existing line would make more sense. The delegates from Aquitaine wished priority to be given to the extension of the LGV Sud Europe Atlantique to the Spanish border.
On 13 April 2006, the RFF administrative committee decided to continue its studies, taking into account the conclusions of the public inquiry. It agreed on a new station to serve Montauban, and decided to study more precisely the two options for Agen (new or existing station). The different options between Bordeaux and Agen are to be thoroughly investigated to determine the route after the public inquiry on the LGV Sud Europe Atlantique line is completed.
The first of three draft laws unveiled by the French Government on 30 April 2008 granted the French Government the right to purchase land and actively seek bidders to build the LGV Bordeaux–Toulouse line. Funding for the line would come as part of a massive programme of expansion of High Speed Lines in France, totalling 2,000 km of additional high-speed rail by 2020. That program was later descoped in the face of budgetary difficulties, but the Bordeaux–Toulouse line currently seems likely to survive, though unlikely to be constructed by 2020.