Engineers at Northampton station say delays and service alterations are 'likely' after a signal fault brought all trains to a stop.
London Midland confirmed the disruption in a tweet at around 2.15pm and said that all trains approaching from both the north and south of the station had come to a standstill.
Engineers are on the scene and lines have now reopened, another London Midland tweet said. However, delays and alterations to timetables are expected until approximately 4.30pm.
Updates to follow.