Train services to, from and through Manchester Piccadilly have been cancelled or changed after a signalling fault disrupted the station.
Network Rail said a cabling issue meant trains could not use platform 8 and engineers were working to fix the problem.
National Rail said the incident was reported at 06:06 BST and disruption was expected until 10:00.
Avanti West Coast, CrossCountry, East Midlands Railway, Northern, TransPennine Express and Transport for Wales services were affected.
Clare Waller, Network Rail’s area director for Manchester, apologised to passengers and said teams were “working hard to fix the problem” and get services back to normal.
Avanti West Coast said four services between Manchester and London Euston had been cancelled because of the signalling fault.
They were the 06:02 and 06:23 from Piccadilly to London Euston and the 09:13 and 10:13 from Euston to Manchester.
Northern said services between Piccadilly and Hazel Grove, and between Piccadilly and Alderley Edge, would also be cancelled.
Other Northern services from Piccadilly were not affected, National Rail said.
Passengers can use alternative Northern services towards Buxton and Crewe via Stockport, while Northern tickets are also being accepted on Avanti services between Manchester Piccadilly and Wilmslow and on the Bee Network 192 bus between Manchester and Hazel Grove.
Passengers were advised to check their journeys before travelling.