The Great Western Main Line from London to Bristol is in the process of being electrified. However, because of cost overruns and delays, on 8 November 2016 the government announced that several elements of the programme would be deferred including electrification south west of Thingley Junction near Chippenham and Bristol Parkway. This will leave Temple Meads un-electrified but the new Hitachi Super Express trains are bi-mode so can operate as diesels around Bristol and can use electricity where the electrification work is complete. The electrification plans do not extend west of Bristol so local services will continue to be provided using diesel trains, with Class 165/166s cascaded from Thames Valley services scheduled to replace the 150/153/158s on local services.