Train drivers mounted picket lines outside railway stations on Saturday as strikes continued in a long-running pay dispute.
Aslef said the 22-month-long row had cost the industry £2 billion, much more than it would have cost to resolve the conflict.
Rail passengers suffered more travel disruption when six operators were hit by strikes.
Some areas of the country will have no services all day on Saturday.
Chiltern, TransPennine Express, and Northern will not run any trains, while there will be reduced services on Great Western Railway, LNER, and Heathrow Express.
LNER said it plans to run 35 services between London, Edinburgh, and West Yorkshire, while no Heathrow Express trains will run before 7.25 a.m. or after 7 p.m.
GWR said services will be reduced, with many parts of its network having no trains all day.
Engineering work means there will be no trains between London Paddington and Reading.
The strikes follow walkouts at Avanti West Coast, East Midlands Railway, West Midlands Railway, CrossCountry, and London NorthWestern on Friday, which crippled services.
Several train operators, including those serving busy commuter routes in the South East, will be hit by a strike on Monday.
A ban on overtime on Saturday, Monday, and Tuesday at 16 train companies is also leading to cancellations and disruption.
Aslef says it wants to meet with train companies and ministers to try to break the deadlock, claiming that the government does not want to resolve the row.
No meetings have been held between the union and the Rail Delivery Group (RDG) for a year, or with Transport Secretary Mark Harper since December 2022.
Aslef general secretary Mick Whelan said: “We’ve done 17 pay deals in the last 12 months across all sectors, nations and regions—freight, open-access, Elizabeth line, and Tube.
“And yet we only have a problem with one place and the place we have a problem with is the Westminster government, who are interfering with our pay deals with the private companies we work for.”
A new law was introduced last year aimed at ensuring minimum levels of service during strikes, but none of the train operators have applied to use it.
A Department for Transport spokesperson said: “Aslef is the only rail union continuing to strike, targeting passengers and preventing their own members from voting on the pay offer that remains on the table.”
A spokesperson for the RDG said: “Minimum service level legislation is one of many useful tools for managing strike disruption, but it is not a silver bullet.”
