Passengers on some morning and evening services during rush hour are travelling on trains that are carrying 60 per cent more people than they were designed to hold, the Department for Transport data stated.

The most overcrowded service, revealed in a ‘snapshot’ in autumn 2012, was the 8.27am Heathrow Express service going to Paddington in London, which carried 786 standard-class passengers, 65 per cent over the capacity figure of 476.