Network Rail staff who are members of the RMT union will take part in an additional strike around Christmas, adding to the walk-outs planned from staff across the rail network in December and January.
The ongoing dispute over pay, jobs and conditions has seen offers rejected and recommended for rejection by the RMT union. Another union, the TSSA, has rejected an offer from rail operators - who run trains - but is considering one from Network Rail, whose staff are responsible for running stations and infrastructure like signals.
ASLEF, the train drivers' union, could add to the strike dates.
