Rail passengers travelling to and from London Euston have been advised not to travel amid warnings of a day of major disruption to journeys after all lines were closed on Sunday.
There will be no services to or from the station on Sunday morning until at least midday due to emergency repairs on downed overhead wires, Network Rail said.
Trains operated by Virgin, London Midlands and London Overground will be affected and delays are expected throughout the day.
A message on the National Rail Enquiries site said: "Customers are advised NOT TO TRAVEL.
"No London Midland and Virgin Trains services will be able to depart or arrive at London Euston until at least 12pm. Tickets valid for travel Sunday 3 December will be accepted on Monday.
"If you must travel, please check the Journey Planner to make sure the line has reopened before starting your journey.
"Trains that do run are expected to be busier than normal, so travel should be considered for later in the day or on Monday where possible."
Virgin Trains customers can use Chiltern Railways, TransPennine Express and Virgin Trains East Coast via any reasonable route until further notice, National Rail said.
London Euston station will remain open despite the line closures.
More than 500m of wires near Wembley, north London, needed replacing after they were damaged at around 3.30pm on Friday.
The cause of the damage is not yet known.
Passengers can check if their service is affected at nationalrail.co.uk