Train passengers will face further disruption over Christmas and the new year as rail workers prepare to stage a fresh series of strikes.
Around 40,000 members of the Rail, Maritime and Transport (RMT) union will take part in eight days of walkouts over the festive period.
The government has condemned the latest round of industrial action, saying it is aimed at causing "maximum disruption".
When are the next train strikes?
RMT members across Network Rail and 14 train operating companies will strike on 13-14 December, 16-17 December, 3-4 January and 6-7 January.
Only a small number of services are due to run on main lines on these days.
There will also be an overtime ban across the railways from 18 December until 2 January.
The services facing strike action are:
Cross Country Trains
East Midlands Railway
South Western Railway
Great Western Railway
Avanti West Coast
West Midlands Trains
Why are rail workers striking?
The RMT is in a long-running dispute with train companies over jobs, pay and conditions, as the cost of living crisis grows.
There has been no sign of a breakthrough since the RMT's first wave of strikes in June, which caused mass disruption. Further walkouts took place in July, August and October.
RMT general secretary Mick Lynch said: "This latest round of strikes will show how important our members are to the running of this country and will send a clear message that we want a good deal on job security, pay and conditions for our people.
"We have been reasonable, but it is impossible to find a negotiated settlement when the dead hand of government is presiding over these talks."
Network Rail said it "will not give up" hopes of reaching a deal, but urged the RMT to return to negotiations with "a more realistic appreciation of the situation".
The Rail Delivery Group said it wanted to reach a "fair deal" after making "real progress" in recent talks with the union.
What has the government said?
The government has called on the RMT and rail operators to resolve the dispute.
A Department for Transport spokesperson said: "Strike action risks putting the very future of the entire industry in jeopardy.
"These strikes are not only damaging the economy but they're cutting off people in need of urgent care, children going to school and hardworking families.
"The rail industry is facing serious financial challenges and is in desperate need of vital reforms to address them.
"We once again urge union leaders to work with employers and come to an agreement which is fair for passengers, taxpayers and workers alike."
Watch: RMT union boss Mick Lynch defends Christmas and New Year strikes