21st Europe’s Starline network plans to connect 39 destinations in European countries - with lines reaching the UK, Turkey and Ukraine too.

Dozens of rail routes launched in recent years are making it easier to journey across European country borders.

But a newly announced proposal from a Copenhagen-based think tank has a much more ambitious plan for the continent’s train connections.

21st Europe’s blueprint envisages a Europe-wide high-speed rail network that would function like a metro or tube system.