The French proposition was to force aircraft that were seen to be resident in France for more than 6 months to adopt an F registration.
Whilst it was claimed by the usual doom-merchants in the UK that this move in some way mirrored American action or was a specific move against FAA operators the truth was rather more mundane. It was a sweeping response by the DGAC in an attempt to deal with various issues surrounding Yaks (and similar) of many bizarre and ill-policed registrations that were flying in France on full Certificates of Airworthiness. The N-reg community was an incidental victim of the move.
In the end, commercial pressure placed (in particular) by EADS killed the proposed legislation, since it would effectively have grounded the many N-reg TBM700C2s that have been sold in France (they are only available on the N). Similar pressure was brought to bear by the operators of various Fractional Ownership schemes which are provided for under the FARs, but not under F-reg operations.
Grounding Yaks proved to be a more direct and less contravertial response to the original problem.
2D