Football fans and festival goers are among those facing fresh travel disruption on Saturday, as more than 45,000 rail workers take part in a further strike over pay and conditions.
Network Rail said only 20% of trains would run, with operators such as LNER and Cross Country affected.
It comes after UK-wide rail strikes on Thursday and walkouts on the London tube network on Friday.
The RMT union’s Mick Lynch said more industrial action was “very likely”.
Speaking to BBC Breakfast, Mr Lynch rejected suggestions that striking rail workers would agree to the current offer on the table if the union put it to a vote.
He added: “I’ll be talking to senior executives in the industry all through next week trying to create solutions to these problems and then we’ll decide whether we need to take more industrial action – but I’ve got to say that it’s very likely given the gap between us at this time.”
The union has also accused the government of blocking the train companies from offering…