With the coming upgrade to the Great Western Main Line, the main line from London to Bristol is due to be electrified by 2016. However, the electrification will not extend beyond the main lines, so Sea Mills will continue to be served by diesel trains, with the current "Sprinter" units expected to be replaced by and "Turbo" units. Stephen Williams, MP for Bristol West; and the group Friends of Suburban Bristol Railways supports the electrification being extended to the Severn Beach Line.