Hundreds more daily train services are being cut in response to pandemic-related staff shortages.
Avanti West Coast, c2c, East Midlands Railway and South Western Railway are introducing emergency timetables from Monday to reduce short-notice cancellations.
Several other operators have taken the same measure in recent weeks due to the impact of the Omicron coronavirus variant.
It was estimated earlier this month that around 10% of rail staff were absent from work.
South Western Railway’s emergency timetable will see it operate 28% fewer weekday trains compared with pre-pandemic levels.
That is compared with the 17% reduction in its most recent timetable.
The firm’s managing director, Claire Mann, said the change is “the most effective means of ensuring our customers receive a reliable service”.
Just one daily return service will operate between the capital and Holyhead, North Wales via Chester.
East Midlands Railway said it is removing 4% of services from its timetable as short-notice cancellations are “incredibly frustrating” for passengers.
This will “protect” those trains which are “important for customers who are still travelling”, it added.
Sixteen services will be removed the weekday timetable of c2c, which operates between London Fenchurch Street and south Essex.
Industry body the Rail Delivery Group said reliability has been boosted by those operators which have already reduced services.
It added that just 2.1% of all trains were cancelled in the seven days to Friday, which is below the annual average of around 3%.
Passengers are advised to check for updates before setting out on their journey, or sign up for automatic alerts from National Rail Alert Me.
Provisional Department for Transport figures show demand for rail travel was at 55% of pre-pandemic levels earlier this week.