Engineers baffled by signalling issues on London Underground’s Northern line

Transport for London said to be considering night tube cancellation as disruption drags on for commuters

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Troubles on London Underground’s Northern line that have disrupted journeys for millions of commuters since Sunday could persist into next week, with engineers still baffled by the cause of the signalling fault.

Transport for London (TfL) is understood to be considering cancelling the weekend night tube service to allow time for extensive investigations if specialist engineers cannot fix the problem on Thursday night.