Campaigns have been stepped up against proposed cuts to train services between France and Belgium, and Ashford International Station in Kent.
There will be fewer services between Ashford and the continent
Members of Kent County Council (KCC) were at a European Commission meeting, which "agreed to press for the upkeep of services".
The Ashford's Future development board has expressed its dismay over the cuts in a formal letter to Eurostar.
Paris trains are being cut and Brussels services will stop from next October.
The proposed changes to Eurostar's passenger services from London to the continent will happen when the new Ebbsfleet International Station opens in north Kent next year.
A Eurostar spokesman said: "Of the 90% of Ashford users who arrive by road, we think up to two-thirds of them will find Ebbsfleet either the same distance or less of a distance to travel."
Ebbsfleet International Station is due to open in October
Despite the cuts to Ashford services, Eurostar said there would be an overall increase in international trains running through Kent once Ebbsfleet was open.
But that has not stopped widespread opposition.
KCC said an online poll showed 95% of the 5,000 participants wanted to travel to Europe from Ashford International.
Campaign group Railfuture questioned why an £80m railway station was having its services reduced only 11 years after opening.
And the Ashford's Future board, overseeing development plans for the government growth town, said Eurostar's proposals would be damaging to its work.
The Eurostar spokesman added: "We will monitor the level of demand that is taking place at Ashford and we can keep timetables under review.
"But we think we've got the stopping pattern right."