There is disruption on East Coast rail line between Newcastle and Kings Cross, and between Leeds and Kings Cross, due to overhead line problems at St Neots.
Tickets are being accepted on the CrossCountry, East Midlands Trains, First Transpennine Express, and Virgin Trains services.
Replacement buses are operating between Peterborough and London, although a very limited number of trains can run via Cambridge.
Services are not expected to run via St Neots until later this afternoon, but with disruption for the rest of the day.
More top news
72-year-old Arthur Bierton from Thirsk was convicted at Teesside Crown Court of abusing two young girls in the 1980s and 90s.
Flying Officer Cameron James Forster and Flying Officer Ajvir Singh Sandhu were killed in a plane crash in North Yorkshire.
Internationally renowned superstar Katherine Jenkins will be performing at Herrington Country Park in Sunderland on Friday 6th May.