The disruption has been caused by damage to the overhead electric wires on a stretch of track between Preston and Euxton Balshaw Lane stations.
Northern initially expected services to resume around 3.30pm. But the rail operator is now warning that regular services might only be restored after the evening rush hour.
Services are not calling at Preston, Leyland, Buckshaw Parkway, Chorley, Adlington, Blackrod, Horwich Parkway and Lostock.
The power failure has left passengers stranded between stations, with bus replacement services picking up stranded passengers.
“The back entrance on West View also remains closed. We apologise for any inconvenience this may cause for people.”
Preston to Lancaster Preston to Blackpool North/South Preston to Bolton Preston to Wigan North West Manchester Piccadilly to Preston
According to Northern Rail, train services running through Preston have been cancelled, with power not expected to be restored until 3.30pm.
Other news: This Wigan man has spent decades crafting stunning walking sticks. Now he wants to sell them for charityThe woman, aged in her 20s, was allegedly struck by a campervan in the car park of a Morrisons supermarket in Preston.
A police spokesman said: “We were called at shortly before 6.25am by the ambulance service to the report of a collision involving a woman and a campervan in the car park of Morrisons on Blackpool Road, Preston.
“A section of the car park has been cordoned off for officers to conduct their investigation into the cause of the collision.
“The back entrance on West View also remains closed. We apologise for any inconvenience this may cause for people.
“The driver of the campervan, a 74-year-old man from Wigan, has been arrested on suspicion of dangerous driving and remains in police custody.”
Staff at Morrisons confirmed that the supermarket remained open but there was limited access to the car park.