Guards on Virgin Cross Country trains are striking today in pursuit of a long-running dispute over pay.
Members of the RMT union are involved in a row with the train company about a deal aimed at reducing working hours.
Guards have been taking industrial action for months, although Virgin insists there has been little or no disruption to services.
Bob Crow, RMT general secretary, said the dispute was “simple” and would cost Virgin just £6 per Sunday shift to settle.
“We warned the company that if they turned down our offer of unconditional talks, an escalation of the dispute was inevitable,” he said.
“Our members entered into a 35-hour week agreement with the company in good faith and they have made it clear that the company’s attempts to undermine their action have served only to galvanise their determination to win a just settlement.”
Crow said the union remained ready to talk with the company, with or without the help of conciliation service Acas.
Virgin insisted it is ready to meet the union to negotiate a deal to end the dispute.