This means that any station to be properly served from London needs expensive manned passport control, security checks, and a spare platform fenced off from others by a de facto international border. International and domestic passengers must be kept separate, too. These hurdles also make it commercially unviable to directly serve other destinations in the U.K. beyond London.
Piling in
Despite these challenges, the London route is deemed so lucrative that companies seem to be piling in.
Another would-be competitor, Gemini Trains, says it still wants to run 11 trains a day through the Tunnel by 2030 despite failing in its application for space at the Temple Mills depot. As of August 2026 Gemini is now looking at opening its own depot in Kent, on the site of a mothballed facility at Chart Leacon.
It has a partnership with global mobility giant Uber, but no trains, track access, nor yet a depot. If it is able to run its planned services, too, it would take the total number of cross Channel return services to 66 a day.
Eurostar has also announced plans to increase its own offering, and says a €2 billion (£1.7 billion) fleet of up to 50 new train sets will be delivered in the early 2030s, allowing a 30 percent increase in its own services and expansion to new destinations including Frankfurt and Geneva.
While the high-speed line on the U.K. side of the channel has plenty of spare capacity for all these plans — it was built with space for eight international trains an hour — whether they can come to fruition will also depend on capacity elsewhere. Train paths in France, Belgium and beyond will need to be secured.
Another major constraint will be passenger capacity at stations. In the international terminal at London St Pancras station terminal, there is already often nowhere to sit once through passport control. The station’s owner has commissioned architects HawkinsBrown to fix this — with a brief to double passenger capacity there by 2028 and more expansions planned in the 2030s. St Pancras sits on a constrained site, sandwiched between neighboring King’s Cross station, the British Library, and a canal — limiting room for expansion.
Speaking last month, Gwendoline Cazenave, CEO of Eurostar, said the U.K. needed “a bold vision to match the private investment on the table.” She called for “more depot capacity, a bold expansion of St Pancras and a seamless border.”