Rail line to be closed between Bristol and Newport over Easter
The railway line between Bristol Parkway and Newport will be closed over the Easter weekend for electrification work in the Severn Tunnel.
From Good Friday to Easter Monday replacement buses will operate between the stations for trains from London Paddington.
Trains from Portsmouth Harbour and Taunton to Cardiff will also terminate in Bristol.
Great Western Rail said journeys would be quicker when the work was finished.
Operations director Rob Mullen said new Intercity Express Trains were providing 6,000 seats a day between south Wales and London Paddington - the equivalent of 75 extra carriages.
Further work is planned for 27 and 28 April when trains between London Paddington and south Wales will be diverted via other routes.