Network Rail has warned that the three-day train strike next week will cause six days of disruption to services.
On lines that are open, services will operate from 7.30am to 6.30pm only and not all stations will be served, it added.
The last trains to and from London will be much earlier than normal.
More than 40,000 staff at Network Rail and 13 train operators are expected to walk out on 21, 23 and 25 June in a dispute over pay and redundancies.
Network Rail said it wants to cut between 1,500 and 2,000 frontline jobs in a bid to reduce costs, improve safety and boost productivity...