Network Rail has apologised for rail delays and disruption between the capital and stations in Milton Keynes and Northamptonshire.
Power lines were brought down at Wolverton near Milton Keynes this morning.
The National Rail Enquiries website has the latest details on the rail disruption.
Dyan Crowther from Network Rail said the lines were re-opening and repair work would continue over the weekend.
Overhead line problems have again brought rail delays in the Northampton and Milton Keynes areas.
Thousands of train passengers are potentially facing severe delays until the end of the week due to "extensive" damage to power cables.