Workers who clean trains which travel between Wales and England are to stage a 24-hour strike on the day of a crucial rugby game between the two countries.
Members of the Rail Maritime and Transport union employed by contractors on Arriva Trains Wales will walk out for 24 hours on March 16 in a row over pay.
Wales play England on that day in Cardiff in the final round of games in the Six Nations rugby union tournament, which will draw huge crowds, many travelling by train.
The union said the action by staff at Churchill's was part of its campaign for a decent pay rise for transport cleaners across the country.
The cleaners voted by 9-1 in favour of industrial action after the union accused the contractors of refusing to make any pay offer.
General secretary Bob Crow said: "This battle on Arriva Trains Wales is now seen as having national significance in the campaign against low pay and exploitation by greedy companies, and RMT will continue to ratchet up the pressure for fairness for this important group of Welsh transport staff as part of our national cleaners' campaign.
"In the face of the insulting zero pay offer from the company, our members have had no option but to fight back in the battle to eliminate poverty pay, and that is why they will be striking next Saturday."