RAIL commuters are facing severe delays after further overhead wire problems were found this morning.
It is not know when normal service will resume.
Engineers were called to Hitchin at 3pm yesterday after similar problems in the area and repairs carried on into the night, causing delays on commuters' travel home.
But the problem still hasn't been sorted and trains are not able to run between Letchworth and Biggleswade and buses are being used to ferry passengers between the stations.
Passengers are stuck at Biggleswade rail station waiting for buses, although a crash on the A1 could be halting buses.
East Coast, Grand Central and First Hull Trains are terminating at Peterborough and not running to London King's Cross.
A First Capital Connect spokesman said: "Services London to Peterborough were severely disrupted from 3pm Monday afternoon and continuing Tuesday morning, affecting thousands of commuters, just as the Christmas getaway began.
"Power cable problems and lack of supply meant no services Hitchin to Stevenage, also affecting routes to and from Cambridge to London.
"Network Rail was working on the cables to restore power all Monday evening and into the night, and they managed to get one of four lines opened.
"By Tuesday morning, this began affecting commuter services again. Commuters faced extended intervals of about to 3 hours as a fleet of buses ferried people between Lechtworth and Biggleswade to Stevenage.
"First Capital Connect are unable to say when through running would be fully restored, and that all customers affected will be able to claim compensation."