The entire line between Newport and Shrewsbury will be closed this weekend for engineering works.
A rail replacement bus service will be in operation between Newport, Cwmbran, Pontypool & New Inn, Abergavenny, Hereford, Leominster, Ludlow, Craven Arms and Shrewsbury.
Rail passengers are being advised to check the National Rail website before travelling.
A number of Transport for Wales services will be affected.
