Southern: Government has two weeks to decide on contract breach
The government has two weeks to decide if Southern rail is in breach of its contract or face judicial review, the High Court has ruled.
The Association of British Commuters (ABC) took legal action over what it described as the Southern "fiasco".
The government has said it will not be publishing any new reports on Southern.
It said an independent report published last week made it clear the responsibility for disruption was "primarily caused" by strike action.
Southern, owned by Govia Thameslink Railway (GTR), has been embroiled in a bitter dispute with the unions over driver-only operated trains.
The Department for Transport said the Gibb report made it clear "the responsibility for disruption... was primarily caused by industrial action led by RMT and Aslef and exceptional levels of staff sick leave."
It added: "We have been considering whether the extensive disruption to the line last year was entirely beyond GTR's control and our decision was due to be communicated to the company imminently.
"We are more than happy to inform GTR of the verdict within the 14 days required by the judge."
The ruling comes as the drivers' union, Aslef, began a new overtime ban.
Clive Sheldon speaking for the transport secretary said Chris Grayling was "fully aware" of the inconvenience being caused to Southern's 300,000 passengers.
Southern has been forced to introduced a revised timetable axing about a quarter of services affecting services in Kent, Sussex, Surrey and Hampshire.
Before the hearing, Summer Dean, of ABC, said: "Passengers are the only people who still don't have a voice in this fiasco, and many thousands of them support us in our efforts to reveal the truth behind the Department for Transport's involvement in Southern Rail."
ABC said ministers acted unlawfully by failing to determine whether managers had breached franchise obligations.