The United Kingdom should soon have better train connections to the European mainland, with non-stop, high-speed services set to connect London to destinations in France, Germany, Italy, and Switzerland.

The new train services, which will run out of the UK's only international train station, London St Pancras International, will expand the current offering of services to Paris and Lille in France, Brussels in Belgium, and Rotterdam and Amsterdam in the Netherlands.

The new services will likely connect the UK capital to Frankfurt and Cologne in Germany, Geneva and Zurich in Switzerland, Bordeaux in France, and Milan in Italy.

The expansion will include an upgrade of the facilities at London St Pancras International, so it can handle 5,000 passengers an hour, instead of the current 1,800. The increased capacity equates to the station waving off five full trains headed for the European mainland every hour, instead of today's two.

The company that operates the station, London St Pancras Highspeed, says it hopes to attract new railway companies to operate some of the new routes. All services to the European mainland are currently operated by a company called Eurostar.

Richard Branson's Virgin Group, a new Spanish company called Evolyn, Netherlands-based startup Heuro, and Germany's Deutsche Bahn are all understood to be interested in joining Eurostar at the upgraded London St Pancras International station and operating new services through the Channel Tunnel, which carries railway lines for around 50 kilometers beneath the English Channel, linking England with France.

Getlink, the French operator of the Channel Tunnel, has given its approval to the expansion plans, with Yann Leriche, Getlink's chief executive officer, saying: "We are keen to drive forward attractive opportunities for low-carbon (travel) with a range of new destinations in Germany, Switzerland, and France. This partnership with London St Pancras Highspeed is essential for accelerating this momentum."

Robert Sinclair, London St Pancras Highspeed's chief executive officer, said the expansion plans are part of the company's "journey to realize a future where high-speed rail is the preferred option for traveling to Europe".

However, neither London St Pancras Highspeed nor Getlink have yet put a timeline on when the upgrade of St Pancras station will be complete, or when the new routes will be operational. And critics of the plans have pointed out that existing Eurostar trains are not thought to be compliant with German railway rules, and that neither Virgin Group nor Evolyn have trains in their fleets that are ready to begin plying the new routes.

Experts believe the upgraded station and the new routes are unlikely to become a reality before 2030, and note that new operators will need to get permission from governments on both sides of the English Channel before they can start work.