Two train operators are warning commuters of disruption due to engineering work over the weekend.
Great Western Railway (GWR) has advised services between London Paddington, Bristol and South Wales will not stop at Didcot Parkway on Sunday.
As a result Chiltern Railways said its services between London Marylebone and Oxford “are likely to be busier than usual”.
The operator said operational challenges also meant customers should check before they travel from Friday until Sunday.
GWR has urged customers “to only travel if absolutely necessary” between London Paddington, Bristol and South Wales on Sunday.
There will be fewer services, which will stop at Reading, but a diversion will be in place adding about 30 minutes to journeys. Anyone still wanting to travel “must make a reservation”.
It also said that due to the late notice of some of the engineering work, journey planners would not be fully correct until they are updated overnight on Saturday.
A full list of the routes affected by the works can be found here.
GWR said there would be reduced services to and from London Paddington throughout November and early December and apologised for the disruption.
Network Rail’s Western route director Marcus Jones said their work to improve the performance of the Thames Valley line was “well under way”.
He said they were upgrading drainage systems and the track which was “essential” to the goal of reducing disruption and improving the resilience of the line.
Chiltern Railways said HS2 viaduct works near Wendover, Buckinghamshire taking place over the weekend may also affect services.
The company’s commercial and customer strategy director Michael Stewart said he “strongly” encouraged customers to check their journeys on the day of travel, as journey planners might not be updated until late in the evening on the previous day.
