Campaigners have raised concerns that a complete rehaul of train timetables is likely to leave some passengers bewildered on the station platform.

This month Govia Thameslink Railway (GTR), which is responsible for Great Northern, Gatwick Express, Southern and Thameslink and are introducing a new timetable in a bid to combat saturated transport links. Southeastern, whose parent company is Govia, is also bringing in a new timetable.

But passenger groups are concerned that many travellers are going to be unaware of the changes, which will come into force on May 20, and how their journey will be affected.

Steve Chambers, public transport campaigner at Campaign for Better Transport, said: “Our train system is at full capacity and this is the culmination of many years of planning and it is vital that now comes into force.

“The only concerns we have is that people will be caught off-guard not knowing about the changes, that is something that is vitally important that the services ensure is done correctly.

“We don’t want to see commuters turning up on Monday morning for their usual 7.02am train to find that there is in-fact no train coming.

“So this is now the key time with a few weeks to go for them to get this spot on and ensure that passengers know what to expect.”