The RMT on Thursday announced a fresh set of strikes set to “shut down” the transport network and cause misery for commuters.
More than 40,000 union members from Network Rail and 14 train operators will walk out on September 15 and 17 in a long-running dispute over pay, jobs and conditions.
The union warned the action will "effectively shut down" the rail network.
Members of the ASLEF union, which represents 96 per cent of train drivers in England, Scotland, and Wales, are also set to strike on Thursday September 15 in a dispute over pay.
Meanwhile rail union TSSA has announced staff at nine train companies will hold a country wide 24-hour walk out, which will coincide with the Labour Party’s annual conference in Liverpool on September 26 and 27.
Unions have repeatedly shut down UK railways over the summer in their battle for higher wages and against job cuts.
RMT general secretary Mick Lynch said: “Our members have no choice but to continue this strike action.
“Network Rail and the train operating companies have shown little interest this past few weeks in offering our members anything new in order for us to be able to come to a negotiated settlement.
“[Transport Secretary] Grant Shapps continues his dereliction of duty by staying in his bunker and shackling the rail industry from making a deal with us.
“We will continue to negotiate in good faith, but the employers and government need to understand our industrial campaign will continue for as long as it takes.”
The Government has said union leaders are choosing “self-defeating strike action over constructive talks, not only disrupting the lives of millions who rely on these services but jeopardising the future of the railways and their own members’ livelihoods”.
A Department for Transport spokesman added: “These reforms deliver the modernisations our rail network urgently needs, are essential to the future of rail, and will happen, strikes will not change this.”