The Eurostar boss has said his trains between the UK and Paris carry 30% fewer passengers.
Chief executive Gwendoline Cazenave said that with post-Brexit border controls and the current level of border staff there were “bottlenecks” at stations.
Eurostar currently runs 14 services a day between London and Paris, compared to 18 in 2019.
Ms Cazenave said the company may not restore some services that were suspended last year due to the issues.
“The point now is that we cannot offer the same transport offer as before in 2019, due to bottlenecks in stations,” she said.
“We have a big problem in Eurostar terminals because of the new boarding conditions between the UK and the EU, because of the impact of Covid, because of the staff in the stations.”
Last year, Eurostar announced it was ending its direct service from London to Disneyland Paris and also stopping calls at Ebbsfleet or Ashford International stations.
It cited reasons including financial hardship due to losses suffered during the height of the pandemic and post-Brexit border controls – with more time needed to stamp UK passenger passports
Asked if services will be restored in the future, Ms Cazenave said: “We’ll see, it depends on how we can deal with the problems of the major stations.”
She said the company’s “goal” was to be “the backbone between major cities” such as London, Paris, Amsterdam and Brussels.
“These are the key cities, these are the key markets… we work for, that’s our most important role I would say,” she said.
Currently, British passengers traveling to the EU must have their passports stamped when crossing the border, which has caused delays.
An Entry/Exit System, or EES, will replace the controls, but the technology has been delayed several times and will now be implemented in late 2023.
However, concerns have been raised that initial registration for the system could cause delays to Eurostar services and lead to queues at the port of Dover, as the scheme sees people entering the bloc from non-EU countries – including the UK – need to register fingerprints and a photo with their passport details.
After travelers have provided their fingerprints and data, that registration is valid for three years. During that time, it must be validated every time someone crosses the border.
Ms Cazenave told the UKTN that Eurostar is “pushing” for a fully digital system, meaning people can register details at home before traveling and it “wouldn’t be a bad customer experience”.
“We know it’s a big deal, we know it’s a really big challenge,” she said.
Eurostar’s boss said the system would still work without “digitalisation”, but added that “a lot of investment, anticipation and staffing is needed.
On Tuesday, Eurostar announced its new brand, a merger between Thalys and Eurostar, and hopes to carry 30 million passengers a year by 2030.