Nearly three in 10 trains run by the operator of the troubled Southern franchise failed to reach their destination on time over a four-week period, figures show.

Only 70.4 per cent of Govia Thameslink Railway (GTR) services from June 26 to July 23 arrived at the terminating station within five minutes of the schedule, according to data published by the Office of Rail and Road.

Govia, which goes through Mill Hill Broadway, West Hendon, Borehamwood and Elstree, Radlett and Watford Junction and St Albans Abbey, was the worst-performing rail operator in Britain for the period.

Southern passengers have suffered delays and cancellations for months as a result of industrial action over changes to the role of conductors and staff shortages, blamed by the company on high levels of employee sickness.

A temporary timetable was introduced on July 11 with 341 fewer trains because of the dispute.

A GTR spokesman said: "We fully recognise that these figures are unacceptable and we apologise to our passengers for this.

"It was another very challenging period for GTR and a frustrating one for our passengers. Punctuality performance was affected in the main by the continuing train crew availability issues and infrastructure problems."

He added: "Our main focus is now on working hard with Network Rail to improve punctuality performance to the levels our passengers expect and deserve."

By Monday around 170 trains will have been reintroduced to the timetable and GTR expects all services to be restored in the coming weeks.

Virgin East Coast services had the second lowest punctuality at 82.2%, followed by Hull Trains at 83.6%.

The average for England and Wales was 87.1%, while Scotland was slightly higher at 91.1%.

The figures are the public performance measure (PPM) used by the rail industry to reflect punctuality and reliability.

To pass the PPM measure, commuter services must arrive at their final station within five minutes of schedule, while long distance services are given a 10-minute leeway.

A spokesman for the Rail Delivery Group, representing train operators and Network Rail, said: "Rail companies are delivering over £50 billion of improvements as part of the Railway Upgrade Plan which will mean more reliable journeys, extra services and new and longer trains.

"This work is causing disruption, including industrial action over changes that will deliver a better service for passengers without compromising safety.

"Nobody wants to see delays but the current disruption will improve in the long run as we deliver the railway the country needs and passengers want."