With 20,000 members of the RMT union striking on Friday and a stoppage by 12,000 Aslef train drivers on Saturday, rail services will be heavily disrupted.
On Friday, about 50% of services will run on all the affected networks, which are mostly based in England, but with some running cross-border routes into Scotland and Wales; while approximately 40% will run on Saturday, with wide regional variations. Here is a breakdown of the services that operators across Great Britain plan to provide on each day.
Avanti West Coast
Friday: One train an hour will run in each direction between London Euston and each of Manchester, Liverpool, Birmingham and Preston, with a limited service to and from Glasgow.
There will be no services to or from north Wales, Shrewsbury, Blackpool, Stoke-on-Trent or Edinburgh, while Macclesfield station will be closed. The first train of the day from Euston will depart at about 8am, and the last will leave shortly after 5pm.
Saturday: No trains.
c2c
Friday: No major impact but 12-carriage trains will not stop at Limehouse, east London.
Saturday: Usual timetable.
Caledonian Sleeper
Friday: All services will be operating via the east coast mainline because of engineering works. Services will not be calling at Motherwell, Carlisle, Preston, Crewe or Watford.
Saturday: The service does not operate on Saturday nights.
Chiltern Railways
Friday: Services will be limited to one train an hour from about 8am until 10pm in both directions between London Marylebone and each of Banbury, Oxford and Aylesbury via High Wycombe; and between Amersham and Aylesbury Vale Parkway.
No trains will run between Banbury and each of Birmingham and Stourbridge Junction, or between Hatton and Stratford-upon-Avon.
Saturday: No trains.
CrossCountry
Friday: A limited service will operate. No trains will run between Birmingham New Street and Cardiff Central or Nottingham.
Saturday: No trains.
East Midlands Railway
Friday: Services will run between 7.30am and 6.30pm. They will be limited to just one train an hour in each direction between London St Pancras and each of Nottingham, Derby and Corby, as well as a handful of regional routes, such as between Leicester and Lincoln.
Saturday: No trains.
Elizabeth line
Friday: The Elizabeth line is not involved in the industrial dispute with the RMT but there will be some alterations to its services. These include no trains between Maidenhead and Reading before 7am or after 7pm, and no trains between Brentwood and Shenfield from 11.30pm.
No Elizabeth line trains will serve the National Rail platforms at Paddington before 7am and after 7pm. These services will start and terminate at Ealing Broadway. No change to trains that serve the Elizabeth line platforms.
Saturday: Usual timetable except that no Elizabeth line trains will serve the National Rail platforms at Paddington before 7am.
Gatwick Express
Friday: No trains, but Southern and Thameslink will serve Gatwick airport until early afternoon.
Saturday: No trains.
Grand Central
Friday: Grand Central is not involved in the industrial dispute with the RMT but there will be minor alterations to its services.
Saturday: Strike action will not affect services but there will be an amended timetable because of planned engineering work.
Great Northern
Friday: A limited service will run, and only between 7am and 7pm. There will be no trains between Ely and King’s Lynn.
Saturday: No trains.
Great Western Railway
Friday: A limited service will run, and only between 7.30am and 6.30pm. The only open routes will be between those starting at London Paddington and finishing in Bristol Temple Meads, Didcot, Cardiff, Newbury and Plymouth. Also open are services between Gloucester and Swindon; Greenford and West Ealing; Slough and Windsor; Maidenhead and Bourne End; Twyford and Slough; Reading and Basingstoke; Oxford and Banbury; Reading and Redhill; Oxford and Didcot (replacement bus service); Cardiff and Westbury; and Bristol Temple Meads and Plymouth. The Night Riviera sleeper service is cancelled.
Saturday: A limited service will run, and only between 7.30am and 6.30pm. The only open routes will be between London Paddington and Bristol Temple Meads; Westbury and Swindon; Cardiff and Bristol; Exeter and Barnstaple; Plymouth and Gunnislake; Penzance and St Ives; and Reading trains to Didcot, Basingstoke and Redhill. The Night Riviera sleeper service is cancelled.
Greater Anglia
Friday: Trains will run between 7am and 11pm. Some routes will have a reduced frequency, but most will have a normal or near-normal service. However, there will be no services between Walton-on-the-Naze and Colchester Town/Colchester, between Hertford East and London, or between Stratford and Meridian Water.
Saturday: A reduced service will run, and only from 7am, with last trains being earlier than normal. Most routes will be closed, including between London Liverpool Street and Cambridge.
Heathrow Express
Friday: Usual timetable until 8.40pm. Last train from London Paddington at 8.40pm, Heathrow Terminal 5 at 8.42pm, and Heathrow Central at 8.47pm.
Saturday: No trains.
Hull Trains
All strike days: Usual timetable as it is not involved in the industrial disputes.
London North Eastern Railway (LNER)
All strike days: A limited timetable will operate.
London Northwestern Railway
Friday: A limited service will run and only between 7am and 7pm. The only open routes will be between Birmingham New Street and each of London Euston, Birmingham International and Liverpool Lime Street.
Saturday: No trains.
London Overground
Friday: London Overground is not involved in the industrial disputes but there will be minor alterations to some services.
Saturday: Usual timetable, apart from no service between Dundonald Road and Wimbledon on the tram before 6.45am.
Lumo
All strike days: Usual timetable as it is not involved in the industrial disputes.
Merseyrail
All strike days: Usual timetable as it is not involved in the industrial disputes.
Northern
Friday: Only a handful of routes will be open, such as between Liverpool Lime Street and Manchester; Leeds and York; and Darlington and Saltburn.
Saturday: No trains.
ScotRail
All strike days: Usual timetable as it is not involved in the industrial disputes.
South Western Railway
Friday: A reduced service will operate, and only between 7am and 7pm.
Saturday: Services will be reduced and there will be no trains on the Isle of Wight.
Southeastern
Friday: A reduced service will operate, with some routes closed.
Saturday: No trains.
Southern
Friday: A reduced service will operate and only between 7am and 7pm. No trains will run in a number of areas, including between Hemel Hempstead and Clapham Junction; London Bridge and Norwood Junction; Southampton Central and Barnham; and Eastbourne and Ashford International.
Saturday: No trains.
Stansted Express
Friday: Services will not start until after 7am.
Saturday: Frequencies will be halved to one train an hour in each direction.
Thameslink
Friday: A reduced service will operate and only between 7am and 7pm.
Services will be split north and south, with nothing running between London St Pancras and London Blackfriars.
Saturday: No trains.
TransPennine Express
Friday: A reduced timetable will operate, and only between Manchester Piccadilly and York, between Preston and Manchester airport, and between Sheffield and Cleethorpes.
Saturday: No trains.
Transport for Wales
All strike days: Transport for Wales is not involved in the industrial disputes but some of its services will be amended.
West Midlands Railway
Friday: A limited service will run, and only between 7am and 7pm. The only open routes will be between Birmingham New Street and each of Northampton, London Euston, Liverpool Lime Street, Wolverhampton, Rugeley Trent Valley, Lichfield Trent Valley, Redditch and Bromsgrove; between Kidderminster and Whitlocks End/Dorridge via Birmingham Snow Hill; and between Stourbridge Junction and Stourbridge Town.
Saturday: No trains.