The train stopped on the Jubilee line near St John’s Wood yesterday evening, meaning that passengers had to be led down the tracks to safety.
The train is one of two that boasts bunting decorations to mark the Queen’s Diamond Jubilee celebrations.
The breakdown was particularly hard on passengers due to the current searing heat in the capital. The Met Office recorded the surface level temperature at Hampstead at 24C when the train stopped. Some had to be given first aid as they waited in the stifling conditions.
TfL has apologised and said it will compensate those evacuated.