Services will also end early, with the last trains leaving before 10pm to allow extra time for overhead lines to be repaired overnight.
The live departure board at the station warned of ‘severe disruption’ with services to Heathrow, Didcot Parkway and Swansea among the cancellations. Trains to Newbury and Worcester Shrub Hill were also scrapped.
Many were left stranded in Reading on Monday night following the Queen’s funeral. Trains to and from Windsor and Reading had been diverted via Waterloo as engineers scrambled to fix the faulty power lines.
Network Rail said some lines had reopened on Tuesday morning but warned: “Major disruption is due to continue throughout the day.”
It said “more extensive damage” was found in the morning, meaning two of the four electrified lines into Paddington would not have power on Tuesday - meaning they could only be used by diesel trains.
A train became entangled in the wires, as did others - causing damage to almost two miles of power cables. An investigation has been launched into the source of the damage.
Both the Elizabeth line and the Heathrow Express only operate electric trains. Both operators were restarting services by mid-morning on Tuesday but train frequencies had been reduced to a half-hourly service.
The main lines into Paddington are also used by Great Western. It warned of “considerable disruption” throughout Tuesday, saying some trains may be terminated at Reading and “stations between Slough and London may not be served”.
It said: “Passengers are strongly advised only to travel if necessary.”
Many passengers had been advised to change trains at Reading, leading to long queues of people at the station on Monday night.
In further travel disruption Tuesday morning, a safety inspection of the track between South Croydon and Oxted meant some services between those stations could be cancelled or delayed until 9am.