Residents are being warned to expect train delays for several hours at Stevenage, Welwyn Hatfield and Potters Bar.

A message on the National Rail website says: “A speed restriction over defective track between Peterborough and Stevenage and an earlier failure of the electricity supply between Stevenage and Moorgate are causing delays to trains between Peterborough and London King’s Cross / Moorgate.”

As a result of the issues, trains between the stations – which include Welwyn Garden City, Hatfield and Potters Bar – may be delayed by up to 20 minutes.

The disruption is expected to continue until 3.30pm.