Transport for London has become involved in a war of words on Twitter after telling a frustrated commuter to "leave early" to avoid delays.

Frustrated by delays to his morning journey, Twitter user @dan_down said:

However, he did not expect this reply from London Overground's Twitter feed:

The advice did not go down well with the Overground user, who criticised their "smart answers" before calling on them to improve their "shoddy service".

TFL's London Overground later apologised for the comment:

The apology did not seem to reduce @dan_down's anger who revealed that he had contacted customer services about the incident.

TfL told ITV London that they were looking into the "extremely unhelpful message".

“We apologise to Dan for sending him this extremely unhelpful message," TfL's Vernon Everitt said.

"Dan is absolutely right to complain and we are looking into the circumstances of how it came about.”