A train timetable revolution is in disarray after dozens of trains were cancelled on day one, with chaos for commuters set to continue for up to a month.

On Sunday the times of more than 3,000 trains operated by the UK’s largest rail franchise changed.

Govia Thameslink Railway (GTR) - which runs Southern Rail, Gatwick Express, Thameslink and Great Northern - have said that the timetable overhaul will mean there are 400 more trains a day and will allow 50,000 extra passengers to get to London during morning peak hours.

However, on the first day of the new timetable dozens of trains had been cancelled before 9am.

The company has apologised, but last week Thameslink admitted on Twitter that it anticipated it will be June 11 before the new timetable is fully operational on its routes. Train drivers and commuter groups have warned that the worst is yet to come.

It also has been claimed by commuter groups that while GTR is advertising that the cancellations are the result of "operational incidents", the problem is actually that GTR has insufficient drivers for its services.