Passengers planning journeys with Govia Thameslink Railway (GTR) companies are being warned that there are likely to be no trains on virtually all of its network on Saturday 30 September and Wednesday 4 October.

This is due to national industrial action being taken by the ASLEF union.

It is also expected that, on the mornings following strike days, services will start later than usual.

Train operating companies involved include Southern, Gatwick Express, Thameslink and Great Northern.

ASLEF has also imposed an overtime ban which means that fewer trains will run on Friday 29 September, and on Monday 2 and Tuesday 3 October as well as Thursday 5 and Friday 6 October. Amended timetables will be in operation which should provide greater certainty of train times and fewer short-notice alterations.

Trains are expected to be busier than normal, especially during peak hours and waiting times could be longer.  Schools have also been contacted in order that they can plan ahead.

It is expected that a limited shutter service will operate between London Victoria and Gatwick Airport on both strike days.  They will not serve intermediate stations and are expected to be extremely busy.

A queuing system will be put in place and passengers are warned that they may not be able to board their chosen service, especially in the late evenings. Passengers are advised to seek alternative travel options to Gatwick and only use the train if their journey is necessary. Since both strike days will affect most of the country, onward travel options from London Victoria are expected to be extremely limited.

Jenny Saunders, GTR’s Customer Service Director, said: “We know how difficult this ongoing national industrial action is for our customers and we’re really sorry for the continued inconvenience it’s causing. So that you can travel with confidence, we’ll be operating the most resilient timetables we can, but when trains are running, they’re likely to be busier than normal, especially in the peaks, and you might need to wait longer than usual. Please plan all your journeys carefully in advance, allowing plenty of extra time, and check again before you set off.