Eurostar last month admitted it was “fighting for survival” with demand down by 95% due to the ongoing impact of the Covid-19 pandemic.

TSAA expressed its “grave concerns” about Eurostar’s future and urged the government to provide financial support to “prevent a financial calamity” for the cross-Channel rail service.

The union also pointed out that the government has given support to domestic rail operators, as well as the aviation industry, but had not given similar help to Eurostar.

Manuel Cortes, the union’s general secretary, said: “The situation at Eurostar is severe, and government must provide support to avoid mass redundancies and serious damage to our only rail link to mainland Europe.

“Our members at Eurostar are facing financial hardship and mental health problems as a result of the ongoing uncertainty, threat of redundancy and related stress. With Christmas just around the corner, it is a desperate situation.

“We’ve heard some big announcements from government on ambitious climate targets, but if they’re serious about decarbonising our economy, then Eurostar – the green gateway to Europe – must be supported through the pandemic.”

In its letter, TSSA urges the government to extend the financial support offered to the aviation sector to international rail, as well as cutting or scrapping track and tunnel access charges, and providing business rates relief.