No end in sight for northern Line chaos as trains run ‘four times per hour’

Passengers using the northern Line faced severe delays following a signal failure near Stockwell station on Sunday evening.

Travellers have been told to 'avoid the northern Line'

The failure has meant fewer trains than normal have been able to run across the length of the line, with Transport for London (TfL) now revealing that despite identifying the issue, there is no end in sight following the delays.

A TfL spokesman said on Thursday that the cause of the problem remained unknown, with specialist engineers drafted in following the failure and have remained on site ever since.

Read more: Petition for women-only carriages on the tube nears 10,000 signatures

Traditionally a line served by 10 trains an hour, the failure has forced a reduced service, with only four trains scheduled to run per hour - a 15 minute gaps between trains.

Safety concerns continue following the failure, with controllers forced to use two-way radios to guide Tube drivers through London Underground tunnels without causing bottlenecks.

The failing signalling system has also extended the gaps left between trains amid increased safety concerns.

In an email to passengers, TfL warned that the potential delays and problems could continue “until later in the week, due to the complexity of the failure”.

It comes as a petition calling for the introduction of women-only carriages on the tube has almost reached 10,000 signatures.

The petition, launched by 21-year-old University College London student Camille Brown, was set up because she has "had enough of women being unsafe".

She noted the public harassment of women on the London Underground as a growing issues, and accused Transport for London of failing in their approach to tackle it.

Just a week ago, Tube drivers have been offered £80,000-a-year in a new pay deal.