Commuters have been warned of disruption for a second day after a train partially left the tracks near Milton Keynes.
London Northwestern Railway said no passengers were on board when it derailed in the Bletchley area on Thursday.
National Rail said trains between Milton Keynes Central and London Euston could be cancelled or delayed by up to 90 minutes throughout Friday.
“Rail replacement buses have been ordered to run in place of the cancelled services and will be in operation as soon as possible,” a company spokesperson said.
Two trains per hour are due to operate between Northampton and London Euston via all stations.
However, problems with overhead wires in the Northampton area have led to additional cancellations.
Specific advice has been given out to passengers travelling on Avanti West Coast and London Northwestern services to avoid the issues as best as possible.
