Rail companies and Network Rail have reduced the scale of the timetable changes planned for December.

This follows widespread cancellations, delays and overcrowding on Govia Thameslink Railway lines caused by a rushed timetable change in May.

Each year, train timetables are changed in May and December to allow for seasonal factors and as a result of infrastructure improvements.

The new timetable introduced on May 20 this year was widely-regarded as one of the biggest in modern British railway history, but due to over-running engineering works, Network Rail published the timetable late and Govia were over-optimistic about whether they could implement it.

Network Rail’s chair Sir Peter Hendy said: “The railway industry has taken a long hard look at its plans for the next timetable change in December and, taking into account recent painful lessons, the industry has scaled back its ambition and tempered it with a more cautious, phased approach to introducing the new timetable.

“While there will still be new services introduced this December, other new services will now be introduced more gradually over the next few timetable changes to help smooth their introduction and maintain a reliable service for passengers and businesses alike.

“The railway is too vital for the health and wealth of our country to risk a repeat of the mistakes of May and this more balanced approach of ambition and caution is absolutely the right thing to do for the millions who rely on our railway everyday.”

Chief executive of the Rail Delivery Group Paul Plummer said: “In parts of the country, many people have suffered unacceptable disruption following the introduction of the new timetable in May for which we are sincerely sorry. The industry is determined to learn the lessons from what went wrong.

“After careful consideration, Network Rail and train operators are acting now to make sure people get a reliable service when the December timetable is introduced, which means some improvements will be delivered more slowly than originally planned.

“As part of our long-term plan to change and improve, we will still be introducing thousands of new carriages and delivering a ten per cent increase in the number of trains running.

“Our ambition is to deliver a once-in-a-generation step change in the quality of rail services is right but reliability for customers must come first and that’s what today’s announcement aims to ensure.”