Govia Thameslink Railway, which runs Southern, Thameslink and Gatwick Express services, says they will mean faster, easier, more seamless, and more reliable journeys into and across central London.
But a number of passenger groups and politicians across Sussex have raised concerns about some of the changes proposed.
In Hastings and Bexhill, plans to axe the direct service from Brighton to Ashford International have been opposed.
Lewes’ MP Maria Caulfield has spoken out against proposals to halve the number of direct trains from Seaford to London, and has also highlighted a reduction in services stopping at Plumpton and Cooksbridge.
Meanwhile Hassocks commuters have raised concerns about the potential loss of direct peak services to Clapham Junction.
The changes will see more Sussex stations served by Thameslink services as well as Southern trains, with new direct routes between Brighton and Cambridge, Horsham and Peterborough, Littlehampton and Bedford, and East Grinstead and Bedford.
When the consultation started, Charles Horton, chief executive officer of GTR, said: “Our networks are some of the busiest and most complex in the world. Passenger journeys have doubled in recent years, the fastest growth in the UK. Sitting still is not an option.
“That’s why we’ve been hard at work, delivering the transformation needed. By improving tracks and stations, introducing new trains and adding more destinations, we’re making sure our passengers’ railway is fit for the future. We are still in transition but the work is nearly complete.
“We started our consultation in the autumn – one of the biggest ever conducted – and we’ve listened and taken on board where possible passengers’ views on the new routes and developed weekday timetables for final comment. They’ve been designed with reliability at their heart, offering new direct routes across London and more seamless journeys.”
Consultation closes at 5pm today (Thursday July 27).
Weekend timetables will be shared later in the year.
Will you be affected by the potential changes? Email the newsdesk.