Trains from Hatfield to London could be unusually crowded as a signalling problem has diverted passengers from a busy nearby route.

Thanks to a signalling problem near Luton, Govia’s Thameslink route, which serves St Albans and Harpenden, is severely disrupted.

Replacement busses are taking St Albans passengers to Hatfield, and Govia, which runs both the Thameslink and the Great Northern routes, says problems could persist until Friday.