A derailed freight train is causing problems between Leeds Station and Wakefield Westgate.
Trains may run at reduced speeds on the Northbound lines.
Some services may be cancelled delayed or revised.
The disruption is expected until 9am.
A spokesperson for LNER, who run the Leeds to London services, said: "Due to a derailed train at Wakefield Westgate trains have to run at reduced speed on the Northbound line. "