Train chiefs at Govia Thameslink Railway today announced a “once-in-a-lifetime” shake-up of the timetable and thousands more seats for commuters.

The much-criticised rail operator promised more trains, faster services, improved reliability, new routes and extra peak time seats through central London.

But travellers, many still suffering reduced services after months of repeated strikes, train cancellations, delays and overcrowding, will have to wait until 2018 before they get the improvements.

Critics will see the move as an attempt to ward off demands by passengers and MPs that GTR should be stripped of the franchise contract for persistent poor service.

Govia's Southern Railway franchise has been hit by months of delays and cancellations caused by strikes over changes to the role of conductors and high levels of staff sickness.

GTR denied the move was in response to the troubles at Southern, saying the improvements were possible because of the redevelopment at London Bridge station and the £6.5 billion Government-sponsored Thameslink programme finally coming on track in 2018.

Hundreds of thousands of commuters will be asked to help form the new timetables by stating which journeys and what time they travel are most important to them.

The consultation runs until 8 December and GTR teams will be visiting stations across the network to talk with passengers and gauge reaction.

The company has set up a special website detailing the changes and is ready to send copies of the proposals to passengers’ homes across London and the south.

Consultation leader Phil Hutchinson said: “We are proposing a complete redesign of the timetable by looking at which journeys are most important to passengers. We are creating more capacity and new cross-London routes with connections to Crossrail and more punctual and reliable services.

“We want passengers and stakeholders to help us shape their future train services so we are consulting, we think, earlier than any train operator has before.”

He said passengers were being asked to “get involved in an open, honest and transparent conversation” about the services they want. “It’s a once-in-a-lifetime opportunity to restructure the timetable.”

The move was condemned as a “PR stunt” by The Association of British Commuters which is raising monies to fund a Judicial Review into the Department for Transport’s handling of the Southern Rail franchise.

Campaign spokesperson Summer Dean said: “This will just be seen as a stunt by us and others. We have been told time and time again by the company they are going to do this, this and this.

“What we want is action now. They are just trying to pull the wool over peoples’ eyes. We are not stupid though they seem to think we are.”

Fact sheets on the proposals can be downloaded at www.thameslinkrailway.com/2018consultation or passengers can request paper copies by post.