Tower Bridge was stuck in the raised position for several hours on Wednesday, causing disruption to traffic and pedestrians.
The incident occurred as the bridge was lowered following a scheduled lift at 10.45am for the MV Dixie Queen to pass through. For 25 minutes one of the bascules was about a foot higher than the other. At 11.10am the bridge was raised fully and remained in that position until early afternoon.
Tower Bridge Road is a Congestion Charge boundary, so diverted traffic may have unexpectedly entered the Congestion Charge zone.
Roger Evans, Conservative transport spokesman on the London Assembly, who was on Tower Bridge when the fault occurred, said: "I have never heard of anything like this happening to Tower Bridge before. I hope that TfL will be sympathetic to motorists if they have been forced into the congestion charge zone. Any motorists forced to make a detour should be allowed to claim a refund on the charge."
A Transport for London spokesperson said: "Vehicles following a diversion into the zone should leave by the nearest available route as soon as possible. If they do so, they should not receive a penalty charge notice (PCN) and there is no need for them to pay the £5 daily charge.
"However, should drivers go further into the zone or stay in the zone for a prolonged period they will be expected to pay the charge.
"Any driver wishing to contest a PCN should follow the representations process as outlined on the PCN."