Passengers have expressed their anger as the Northern Line enters its fourth consecutive day of disruption.

A fault with the signalling system has caused severe delays, hampering journeys between Camden Town and Morden via Bank.

Speaking about the disruption, Transport for London (TFL) director of customer service, Brian Woodhead, said: “I am extremely sorry for the disruption that Northern line customers are experiencing this morning and for the disruption to their journeys yesterday.

“This has been caused by an issue with the signalling system in the Kennington area.

“Our engineers are working hard to fix the problem and get services back to normal as soon as possible.”

But passengers have expressed their frustration with the delays. Jack Welby, from Edgware, said the problem was causing “mayhem”.

He said: “TFL need to carry out a proper investigation and give a promise that this won’t happen again.

“The work has been going on for ages and is causing mayhem to get to work.”

Passengers also took to twitter to share their views on the problems with the Northern Line.

Jeanine Pacon tweeted: “This service is absolutely appalling and frankly, sending commuters to buses (which are definitely not enough and would add at least 40mins to the journey anyways) just doesn't cut it anymore!”

One user asked if the service would be running as normal tomorrow (July 10), although the Northern Line twitter page could not confirm this.

It tweeted: “Hi, very sorry for the disruption to your journey. Sadly I can't make any promises about tomorrow but we're doing all that we can to restore the service back to good. I'll update the feed as soon as this changes.”

People have been advised to avoid journeys with the Northern line as much as possible. Tickets are currently being accepted on local buses, London Trams, South Western Railway and Thameslink.