Eurostar trains will not stop at stations in Kent before 2022, raising fears of job losses.
The train operator said it had been hit by an “unprecedented” fall in bookings as a result of the coronavirus crisis.
Eurostar trains have not been stopping at Ashford International or Ebbsfleet International stations since March, but that has now been extended to 2022.
The Transport Salaried Staffs Association (TSSA) urged the Government to intervene in a bid to avert job losses.
A Eurostar spokesman said: “Covid-19 has had a severe impact on the travel industry and on our business and we continue to operate in very challenging conditions. We have experienced an unprecedented fall in demand, with bookings down by 90% compared to last year.
“The environment remains very unpredictable and has been exacerbated by quarantine restrictions which are now across all of our markets.
“Given the uncertain outlook, it is crucial that we adapt and take action to reduce our costs so that we protect our business for the future.
“In 2021, therefore, we will reduce our timetable, focusing only on our core routes and destinations where we see the highest demand.
“As a result, we have had to make the very difficult decision not to reopen Ashford International or Ebbsfleet International stations before 2022.
“We have not taken this decision lightly and have given this considerable thought but given the severity of the situation we have to take action.”
Manuel Cortes, general secretary of the TSSA, said: “We will do all we can to work with the company to protect jobs, but we must see meaningful discussions for our members about options for those working at these two stations.
“Frankly the extended closure of Ashford and Ebbsfleet is another clear sign that Eurostar needs help from the UK Government – something I called for months ago.
“Ministers can’t be allowed to sit on the sidelines,they must act now. The Transport Secretary and Chancellor have to give Eurostar the proper support package it badly needs so that it can keep going under the present circumstances.
“Eurostar provides a green strategic link between Britain and our European neighbours, so retaining these jobs and services will significantly increase the chances of Eurostar being on a firm footing as services return to near normal in the months ahead.”