The Senate tax proposed is aimed to apply to the first sale by the owner of a property within 1.5 kilometers of a station in the Ile-de-France region during a 15-year period. It would not apply to sales by a developer. The tax would be capped at 5% of the sale price. But French real estate associations called the plan "inefficient, unjust and dangerous" and argued that it would deter investment in the areas concerned. The proposed tax is intended to help finance the new transport infrastructure, the main feature of which is a 140km figure-eight automated metro line linking the main business and residential areas of Greater Paris.

Paris Region Minister Christian Blanc said the central government will provide an initial €4bn for construction of the new system, and Société du Grand Paris, a new body to oversee the construction of the network, will raise further funds from financial markets.