Passengers are facing delays and cancellations on trains today (Friday) due to a signal failure.
UPDATE: The fault has been fixed and all lines have reopened. Alterations and delays to services continue to passengers advised to check before they travel
Virgin Trains and London Northwestern are advising all passengers to check before they travel today due to severe disruption on all lines due to a signalling fault between Milton Keynes and Watford Junction.
Disruption is expected until 1pm, according to Virgin.
Rail replacement services are in place and tickets are valid on other rail services.
For the latest updates check here for Virgin and @LNRailway on Twitter for London Northwestern.