In the last few moments, a Volotea scheduled flight from Marseille to Caen has declared an emergency and it initiating a diversion to Nantes.
Volotea flight V72580, operated by an Airbus A320-200 from Marseille (MRS) to Caen (CFR) has declared a general emergency enroute, squawking 7700.
The flight is currently initiating a diversion to Nantes. Flight data from RadarBox.com shows the aircraft executed a diversion as it approached Paris airspace; executing the unscheduled diversion to Nantes in the west of France.

The aircraft has initiated a descent below ten thousand feet and has executed a hold in the Nantes area, possibly for traffic sequencing, and now appears to be continuing its approach.
The nature of the emergency is as yet unknown, though the diversion to Nantes may suggest a technical or mechanical consideration. The carrier Volotea has an operating hub at Nantes International Airport.
It should be noted that this is speculation, and the nature of the emergency is a yet undisclosed.

The aircraft in question is an Airbus A320-200, registered EC-NTL; a 14 year old aircraft belonging to the carrier Volotea.
Flight V72580 is now conducting a straight-in approach to Nantes Atlantique Airport (NTE) RWY21.

This is a developing story. Please check back for updates.