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 next week on 21, 23 and 25 June in a dispute over pay and redundancies.
The RMT and Unite are also taking part in industrial action which will affect the London Underground on 21 June.
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.
Andrew Haines, Network Rail chief executive said: “Talks have not progressed as far as I had hoped and so we must prepare for a needless national rail strike and the damaging impact it will have”.
The company added that only around half of Britain’s rail network will be open on strike days with a very limited service running on lines.