Only a fifth of services will operate and half of the lines will close as 40,000 members of the Rail, Maritime and Transport (RMT) union at Network Rail and 13 train operators leave for the third day this week.
However, train companies and unions are moving closer to a deal, senior rail sources said.
Network Rail bosses hinted last night that they had put together a package that meets one of the RMT’s key demands to end the strike action.
The state-owned company had previously refused to rule out redundancies as part of efficiency cuts it demanded in return for improved wage offers.
But any breakthrough will be too late to stop today’s action.
It means several seaside towns have no amenities, including Bournemouth, Blackpool, Margate, Llandudno and Skegness. Cornwall will also have no trains.
Operators tell passengers to “travel by train only when necessary” and to check their journey ahead of time.
A source said that while stations were “relatively quiet” during the weekday strikes, with many commuters working from home, there was “nervousness” about what will happen today.
Steve Montgomery, chairman of the Rail Delivery Group, which represents operators, said yesterday: “We are very disappointed that the RMT leadership has decided to continue tomorrow’s strike, and the union leadership has chosen to take action that will protect the millions. will seriously hinder people who had plans over the weekend.”
“While we do our best to minimize disruption to passengers, our advice is to travel only when necessary. And if you are going to travel, please plan ahead.”
Passengers with pre-booked tickets for today can travel tomorrow or Monday instead, or request a refund.
Yesterday, services wavered from a knock-on effect from Thursday’s strike as signalmen and control room staff refused to show up for night shifts.
RMT leader Mick Lynch claimed its members “stand up for all working people trying to get a raise and some job security”.