Trains on the West Coast Mainline are due to be severely disrupted today after a power failure on the line.
Passengers are being urged to check their journeys at nationalrail.co.uk and follow alternative travel advice from West Midlands Railway and Avanti West Coast.
Miles of signalling lost power in the early hours between Milton Keynes and Watford.
Phil Barnes, operations director at Network Rail, said: “I’m sorry passengers journeys won’t go as planned today. We have lost power on six miles of railway in the Leighton Buzzard area, which means that most services in and out of Euston will be cancelled.
“We’re working quick time to get this fixed and services back up and running as quickly as possible, so passengers can travel as normal. Please check National Rail Enquiries before travelling today.”