There will be very few trains each day from the start of the industrial action on June 21 – which will last until Sunday, June 26 – and trains are expected to be crowded with possible delays.
There will be no service at all on many lines on the strike days, while others will see late starts and early finishes – as early as late afternoon – throughout the period.
And as the industrial action is affecting the whole country, there will be no replacement buses and ticket acceptance with other local rail and bus operators.
Govia Thameslink has also said there will be a greatly reduced service based on an amended Sunday timetable (about 60% of weekdays) each day following a strike - due to the impact of the previous day. Crowding and delays are expected throughout.
Tuesday 21, Thursday 23 and Saturday 25 June
Many stations and routes will be closed. Trains will only be able to run during limited hours from around 7.15am and will finish in the late afternoon. There will be no alternative travel options after the last trains. This means, if you do have to travel, you should carefully check the first and last train for your station. Expect these trains to be very busy. Transport for London is also expecting Tube strikes on Tuesday 21 June.
Two trains per hour will run between King’s Cross and Peterborough, calling at King’s Cross, Finsbury Park, Stevenage, Hitchin, Arlesey, Biggleswade, St Neots, Huntingdon and Peterborough only.
Meanwhile, two trains per hour will run between St Pancras International and Bedford, calling at St Pancras International, West Hampstead Thameslink, St Albans City, Harpenden, Luton Airport Parkway, Luton, Leagrave, Harlington, Flitwick and Bedford only.
And two trains per hour will run between St Pancras International and Luton, calling at St Pancras International, Kentish Town, West Hampstead Thameslink, Cricklewood, Hendon, Mill Hill Broadway, Elstree & Borehamwood, Radlett, St Albans City, Harpenden, Luton Airport Parkway, Luton.
Wednesday 22 and Friday 24 June
Services will also be severely disrupted and will run on an amended Sunday service. No trains will start running before 7.15am, meaning the first train may reach your station much later than this. Journey planners for these days are expected tobe updated on Saturday, June 18.
Sunday 26 June
No trains will run before 7.15am. After that the regular Sunday service will run. These changes will be available in Journey Planners on Saturday, June 25.