One in ten train disruptions caused by staff shortages

The figures showed there were 1.93m 'disruptions' between April 1, 2013 and December 12, 2015. A lack of staff was blamed for 9.42% of these.

Commuters in suburban London suffered the most, with Govia Thameslink Railway being the worst-affected operator. The company - a joint venture between listed firm Go-Ahead and French multinational Keolis - operates the Thameslink, Great Northern, Southern and Gatwick Express services.

It experienced 62,000 staff shortage incidents during the period, accounting for 13.6% of its cancellations and delays.

The winner, with the lowest proportion of delays caused by staff shortages, was Virgin Trains East Coast, at 2.6%, followed by Virgin Trains West Coast, at 3.7%.

For much of the period, however, the East Coast franchise was not operated by Virgin, but by the government's Directly Operated Railways before being re-privatised on 1 March 2015.

The Department for Transport claimed it closely watched the number of delays and cancellations, and held operators to account if too many were disrupted by staff shortages - though it did not define how many disruptions that was.

A spokesman for the Rail Delivery Group, which represents train operating companies and Network Rail, told the London Evening Standard that being unable to run a journey because a member of staff wasn't available was an occasional occurrence.

"Disruption to services, for whatever reason, means that train crews can be displaced and physically in the wrong place to crew a scheduled train. Other reasons, including sickness and annual leave, also have an impact," the unnamed spokesman told the newspaper.