Commuters have faced delays on the line for the last three days, since the service was first impacted on Sunday (October 19).
Transport for London (TfL) says that the severe delays are due to a signal failure being fixed at Stockwell station.
This problem has been ongoing, continuing onto the morning today (October 22).
According to an alert sent by the customers information team for TfL, disruption on the Northern line could possibly last “until later in the week” due to “the complexity of the failure”.
The message read: “The issue has been ongoing for a few days, but we want to reassure you that our teams are working to resolve the issue as soon as possible.”
TfL has also advised online that people “avoid the Northern line route where possible”, adding that “you will find it quicker to use alternative routes if you can”.
This paper has seen that services have been spread out as far as nearly 16 minutes apart this morning.
One person said on X: “The Northern line has been obliterated for three whole days by ‘signal failure’, we are not a serious country I’m afraid.”
Another person wrote: “How can there be MORE delays on the Northern line.”
Tickets are being accepted on London buses, trams, South Western Railway, Thameslink and Southeastern trains.
