The Government committed in last year’s rail White Paper, “Delivering a Sustainable Railway”, to keep the case for further rail electrification under review. The improving business case suggests great potential for a rolling programme of electrification, and the Department continues to work with the rail industry to explore how the cost of electrification can be reduced, and to prioritise schemes. A number of officials are at times engaged with this work, and as a result, it is not possible to provide a simple figure. Upgrades of existing electrification infrastructure are a matter for Network Rail.