Christmas could be ruined for millions of rail passengers because of more strikes, unions warn.
The RMT said travel over the festive season will be derailed if a settlement cannot be reached with bosses and the Government.
That could mean repeats of today – when an estimated 2.5m train journeys were disrupted as 54,000 workers staged a nationwide walk-out.
RMT assistant secretary Eddie Dempsey said: “We’re in it until we win it. It’ll affect Christmas.
“The way things are, we’re going to have to get creative.
"I won’t let the cat out of the bag, but we will alter our industrial position if we don’t see some movement in the next short period.”
General Secretary Mick Lynch, added: “Strikes will go on until we get a settlement.
"We don’t want to continue strikes through Christmas, but if there is no settlement they will continue.”
Staff from four unions refused to work today in the dispute over pay and conditions.
Disruption will continue next week as members of two unions are due to walk out on Wednesday.
And next Saturday 40,000 RMT members, employed by Network Rail and 15 train operating companies, plan to strike for 24 hours.
The Government says strikers are “punishing the very people unions claim to stand up for”.
The Department for Transport added: “We urge union bosses to reconsider this divisive action and instead work with their employers...to agree a way forward.”
Chancellor Kwasi Kwarteng has announced moves to ensure minimum service levels during strikes.