Rail passengers face widespread disruption due to major engineering works on several lines.
Affected routes include services run by Great Northern, Thameslink, Southern, LNER, Grand Central, Hull Trains, and Lumo.
The works will take place on different days affecting various areas, with Sunday, June 15 expected to be the most affected.
From 10.45pm on Sunday, June 8 to 4.45am on Monday, June 9, lines around Stevenage will be closed for overnight engineering work.
During this time, replacement buses will run between Hertford North and Stevenage.
Buses will also replace trains between Stevenage and Letchworth Garden City.
Trains will not stop at Hitchin or Arlesey.
Buses will run between Stevenage/Hitchin and Biggleswade.
Welwyn to Potters Bar
Between Tuesday, June 10 and Friday, June 13, engineering works will slow down late-night and early morning services through the Welwyn Garden City and Potters Bar corridor.
From 11.10pm to 5.10am each night, trains will take longer on the following lines: Great Northern services between London Kings Cross and Cambridge, Royston and Kings Lynn.
Thameslink services between Brighton and Cambridge, and Horsham/London Kings Cross and Peterborough.
No trains will run between London Bridge and East Croydon/Crystal Palace via Sydenham throughout the weekend of June 14 and 15 due to further works.
Southern
Buses replace trains between London Bridge/New Cross Gate and Crystal Palace.
Diversions and amended services include London Bridge to Caterham via Peckham Rye, and London Victoria to London Bridge only operating to Crystal Palace.
Saturday-only cancellations on London Bridge to Epsom, London Bridge to Uckfield (running from East Croydon), and East Croydon to Watford Junction (running from Clapham Junction).
Ticket acceptance includes London Bus route 157, the Jubilee line between London Bridge and Canada Water, and London Overground between Canada Water and New Cross Gate.
Thameslink
All weekend: trains between Cambridge, Peterborough and Bedford, and Brighton, Three Bridges and Horsham will be diverted with longer journey times.
No calls at Mitcham Eastfields, Mitcham Junction, Hackbridge, or Carshalton — passengers should use Southern alternatives.
Until around 10am Sunday, Sutton services start or terminate at Herne Hill, Kentish Town, or Loughborough Junction.
Major shutdown on Sunday, June 15: Kings Cross to Peterborough closed
The most significant disruption comes on Sunday, June 15, with all lines between Peterborough and Potters Bar closed as part of the £1.4 billion East Coast Digital Programme.
Affected operators include:
Grand Central
No services to/from London Kings Cross.
Great Northern & Thameslink
No trains between London Kings Cross-St Pancras and Finsbury Park, Peterborough, Royston and Potters Bar, and Hertford North and Stevenage.
Limited services will run: Kings Lynn, Ely, Cambridge and Royston, Potters Bar and Moorgate, Hertford North and Moorgate, and London St Pancras International and Brighton.
Replacement buses in operation between Potters Bar and Hitchin, St Albans City and Stevenage (via Hatfield), Luton Airport Parkway and Stevenage (via Hitchin), Hitchin and Peterborough, and Bedford and Peterborough (via Huntingdon and St Neots).
LNER
No LNER trains between Peterborough and London Kings Cross.
Replacement coaches between Peterborough and Bedford for connecting services.
Hull Trains
A reduced service via London St Pancras, missing key stops including Doncaster, Retford, and Stevenage.
Lumo
A skeleton service between Edinburgh and Peterborough, with buses covering the gap to Kings Cross.
The disruption is part of the East Coast Digital Programme, an upgrade to introduce digital, in-cab signalling for a more reliable and sustainable railway.
This weekend’s work includes high-speed signal testing between Welwyn Garden City and Hitchin, and preparation work between Biggleswade and Peterborough.
Ricky Barsby from Network Rail said: “We thank all passengers for their patience and understanding as we prepare the network for a more modern future.”
Passengers are advised to check their journey using the National Rail or TfL planners and allow extra time if travelling on affected routes.
