A leading rail operator which has been under fire for delays caused by strikes and staff shortages is planning the "biggest timetable shake-up" in a generation.

Govia Thameslink Railway (GTR) said it wants to boost capacity and "completely recast" many new connections in the south of England to London as well as Bedford, Peterborough and Cambridge.

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 said the planned changes from 2018 will lead to greater reliability on Southern's inner London services, new Thameslink services from Kent and a "massive increase" in Thameslink trains at London Bridge.

Phil Hutchinson, who is leading a public consultation for GTR on the plans, 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.

"Operationally, each route would be self-contained so that if a problem occurs it does not affect other routes.

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

"This is a real opportunity for passengers and stakeholders to get involved in an open, honest and transparent conversation about what the train service should be in the future.

"This is about creating better connections and more capacity. It's a once-in-a-generation opportunity to restructure the timetable to give passengers more trains and the much better reliability we all want.

"Ultimately this will put the Thameslink route at the heart of the UK rail network."

Mick Cash, general secretary of the Rail, Maritime and Transport union, said: "Passengers don't want to be consulted on how services may improve in almost two years' time. They want action now to end the daily chaos to their journeys.

"This can only raise suspicions that the Southern spin machine is at full tilt to obscure the reality of cancelled train services and their plans to get rid of guards in their bid to put profit before safety."