Train driver members of the RMT at 14 rail operators will strike on February 1 and 3 in the long-running dispute over jobs, pay and conditions, the union announced.
General Secretary Mick Lynch said: "Our negotiations will continue with the rail operators to create a package on jobs, conditions and pay that can be offered to our members."
Earlier members of the Aslef union also announced they will walk out on February 1 and 3 - causing widespread travel disruption across the country.