A new partnership of local authorities and regional development agencies is campaigning for a high-speed rail (HSR) line from London to South Wales and south-west England.
The Great Western Partnership has been set up to promote the economic and environmental benefits of an HSR line west of London.
According to the South West Regional Development Agency, an HSR line would reduce the journey time from London to Cardiff to around 70 minutes and the time from London to Bristol to 60 minutes.
It is believed an HSR line could also release capacity on the existing rail network, which can be used for commuter travel and freight.
An HSR line would build on the programme of electrification of the Great Western Main Line from London to Bristol in 2016 and to Cardiff and Swansea in 2017, which will improve current journey times but not achieve HSR speeds.