I have a First Great Western train that will get to London St Pancras at 5.46am and my Eurostar train leaves at 6.19am, how long does it take to walk from the underground station to the Eurostar train? Will I have time to get there? What is the underground station called that is at the St Pancras station? I am really worried that I won't get to my Eurostar train on time. I found out that check in closes 30 mins before the train leaves after booking the tickets. :(