[13][14] During July 2020, it was announced that a consortium headed by the French civil engineering firm Vinci Construction Grands Projets had been awarded a contract for the construction of several major elements of tunnel, including four Avrieux shafts of up to 500 m (1,640 ft 5 in) depth, and the conventional excavation of multiple galleries and seven caverns at the foot of the Villarodin Bourget–Modane decline.

This first €390 million lot of the base tunnel was constructed by a joint venture of Batignolles TPCI, Eiffage TP, Ghella, CMC, Cogeis and Sotrabas.

Egis and Alpina provided project management[16] Contracts for the Mount Cenis Base Tunnel were awarded in July 2021: The approach routes are less advanced; planning is under way on the French side, but on the Italian side the proposed route has had fierce controversy, particularly in the Susa Valley the location of the Eastern portal, with a No TAV (no to high-speed rail) movement.

[19] As a result of protests against the original alignment of the tunnel in the Susa valley, it was decided to increase its length from 52 to 57.5 km (32.3 to 35.7 mi).

[20][21] The cost of the joint Franco-Italian section (from Saint Jean de Maurienne to Val Susa) has been estimated at 8 billion euros (in January 2018 value).

[10][11] However, a 2012 report by the French Court of Audit questioned the reliability of the estimated costs of the tunnel, as well the projected traffic volumes.

[24] A stated aim of the project is a modal shift from road to rail for freight traffic over the Alps, as well as more passengers travelling by train rather than airliners, both of which achieve a reduction in CO2 emissions.