Auto Express in Britain says that unnamed Rolls Royce sources have hinted that the prestigious coach-builder is working on a plug-in hybrid version of its Phantom sedan.

Rumours of an electric Roller are not new, but this is the first mention of an internal-combustion range extender (which adds plausibility, considering that the three ton weight of the Phantom would otherwise necessitate a truly monumental battery pack).

With its Vision EfficientDynamics concept car, parent company BMW recently revealed that it has developed just the type of drive-train being mentioned in connection with the Rolls.   According to Auto Express,  the source also indicated that the electric Phantom would be using a Lithium Ion battery pack, the same type of battery BMW is currently using in its electric Mini Cooper.   No time table for this development was mentioned.