DB is more involved in UK rail then you might think.
DB owns Arriva Trains which in turn operates:
Cross Country Trains
Grand Central (an ‘open access’ operator)
Arriva also has a majority stake in Alliance Rail Holdings. This firm wants to offer rival services between London and the North.
The ICE trains can operate over HS1 (the high-speed line linking London with the Tunnel) because it’s a brand new line and was built for European high-speed trains.
But as AnthonyDunn notes there may be problems operating the ICE trainsets beyond the capital because of the UK’s restricted loading guage. Much will depend on the route.
The Eurostar trainsets which used to run over the ‘classic lines’ linking London Waterloo with Folkestone (in the days before St Pancras opened) were specially built for the UK loading guage.
That is why a small fleet of regional Eurostars was built to operate international trains from Northern cities (Edinburgh and Manchester, for example) right through the Tunnel to Brussels and Paris.
Details of what Eurostar planned and what actually happened can be found within our historical Snapshot page appearing in our current (June) issue.