Article R2324-4 of the French Public procurement code
The purchaser may, for the award of a defence or security contract, use the competitive dialogue procedure referred to in article L. 2124-4, when at least one of the following conditions is met: 1° The purchaser is objectively unable to define alone and in advance the technical means capable of meeting its needs; 2° The purchaser is objectively unable to establish the legal or financial package for a project.