Workers at train maintenance company Arriva Traincare were set to walk out on Friday 18 August over their bosses’ latest refusal to improve a pay offer.
The RMT union members work at the firm’s five depots in Bristol, Cambridge, Crewe, Eastleigh and Gateshead.
RMT general secretary Mick Cash said, “The employer did not table any improvements to their original pay offer. By the close of talks they had resorted to hurling personal insults at the union’s negotiating team.
“It is now crystal clear to RMT that the company are determined to treat our members like dirt.”
The union previously led a walkout in May. Action short of strikes is set to run from 9 to 17 August.
The RMT has confirmed that it will be meeting with Southern rail next Monday in the long-running guards’ and drivers’ disputes over the basic principle of rail safety.
RMT had hoped to get a meeting with the company this week following earlier talks with the secretary of state for transport but this has been delayed.