Due to Network Rail planned engineering work we expect significant disruption to service this Sunday 30 March.
No trains will operate between London Paddington and Reading before 0900 due to emergency repairs Network Rail are completing between Reading and Twyford.
Further works along the mainline between Didcot Parkway and Swindon means GWR trains will need to use alternative routes to serve Bristol and South Wales all day.
After 0900 a significantly reduced, amended timetable will be in place for services between London and Bristol Temple Meads, and South Wales - operating on a diversionary route from Reading to Bath Spa, before continuing to Bristol Temple Meads; Bristol Parkway; Newport and Cardiff.
Trains on this route are expected to be very busy, and journeys will take much longer. Services may also be cancelled or delayed at short notice.
On Saturday (29th) last trains between London Paddington and Reading will also leave much earlier and customer should check their journey on Saturday so that they don’t get caught out.
We're sorry for the impact this will have on your journey. We advise customers to change plans if possible, to travel the day before or after, and to only travel on Sunday if absolutely necessary.
Because of the very late-notice changes, and the complexity of updating timetable systems, journey planners will not show changes correctly before Sunday morning.
To help customers, those who have already bought tickets on the route affected for Sunday 30 March will be able to use them on Saturday 29 March or Monday 31 March, or you can claim a full refund at GWR.com/Refunds, according to the usual terms and conditions of the ticket type.
Replacement buses will operate between Didcot Parkway and Swindon; Reading and Swindon; Bristol Parkway and Swindon, plus Bath Spa and Swindon.
Train shuttle services will operate between London Paddington and Reading/Didcot Parkway. Trains will also run between Swindon and Cheltenham Spa, and between Chippenham and Westbury and Frome.