Some trains passing through Welwyn Garden City, Hatfield and Potters Bar have been delayed up to an hour this morning following an electrical supply problem near Alexandra Palace.

Due to failure of the electricity supply earlier this morning at Alexandra Palace some northbound lines are disrupted.

Train services running through Alexandra Palace are returning to normal but some services may still be delayed or revised. Disruption is expected until 10am.

Great Northern states online: “The power has been restored and we are working to restore the train service to the normal timetable as quickly as possible.

“We are sorry for the problems this disruption will cause you.”