Great Western Railway is advising intending passengers that as well as the Christmas Day and Boxing Day shutdown, some services will be severely disrupted either side of those days.

Between London Paddington and Reading there will be no trains on Sunday, 24 and Wednesday, 27 December because of engineering work.

Most services will start or terminate at Reading instead of London Paddington, but a limited number of Great Western Railway and Elizabeth line services will run between Reading and Ealing Broadway, from where District or Central line Underground services run to central London. The Elizabeth line will not operate between Ealing Broadway and London Paddington.

Alternatively, Great Western Railway tickets can be used on South Western Railway services between Reading and London Waterloo, or on Chiltern Railways between Oxford and London Marylebone.

There will be no Heathrow Express services; anyone travelling to Heathrow Airport from central London should use the Piccadilly line instead.

Services from Cardiff to Portsmouth Harbour will not stop at Southampton Central o Sunday, 24 December, and from Wednesday, 27 to Friday, 29 December,  but will divert via Eastleigh before resuming their normal route at Fareham. Passengers for Southampton Central should change at Eastleigh where rail replacement buses will be provided.

Further information about Christmas travel arrangements can be found at GWR.com/Christmas.

If you need to travel on 24 or 27 December, please allow plenty of time to reach your destination as journey times will be significantly longer than normal. Service will also finish earlier than usual on Sunday, 24 December, and all journeys will need to be completed by approximately 22.30.

Reservations for trains to Devon and Cornwall between 11.00 and 15.00 on Friday, 22 and Saturday, 23 23 December are almost sold out, and those looking for a more comfortable journey should travel before 0930.

Dean Haynes, GWR s Station Manager for London Paddington, said: “As we continue to invest in our railway, we will only be able to run trains to and from Reading and Ealing Broadway on 24 and 27 of December.

“To keep you moving, we have been working with other train companies to provide alternative routes. However, if you can travel on the days before or after, you should consider doing so because journeys will take much longer while the work takes place.”

Joanna Grew, Network Rail s Industry Programme Director, said: “Over the Christmas period, from Sunday, 24 to Wednesday, 27 December, we will be carrying out essential preparatory drainage and railway infrastructure works as part of the construction of HS2 s new station at Old Oak Common near London Paddington.

“As part of this preparation, we also need to close the railway into Paddington on Sunday 26 November where we will also be completing essential railway works between Slough and Paddington which will enable a more reliable railway.

“We appreciate there is never a good time to disrupt journeys but whenever possible we do this at times when fewer people are travelling, such as at Christmas, on bank holidays or at weekends.

“We thank passengers in advance for their patience and urge them to please check before they travel.”