Eurostar is quite exceptional. They recommend 30 minutes.
There's a passport check, and a 30km undersea tunnel, which is probably considered a terrorist target. Knives, alcohol etc are permitted, but not compressed gas or liquid fuel. (I tried this once, on a camping trip.)
You can take an almost identical train from King's Cross to Glasgow, arriving 5 minutes before departure (or less, 2 is the minimum recommended time).
There's a passport check, and a 30km undersea tunnel, which is probably considered a terrorist target. Knives, alcohol etc are permitted, but not compressed gas or liquid fuel. (I tried this once, on a camping trip.)
You can take an almost identical train from King's Cross to Glasgow, arriving 5 minutes before departure (or less, 2 is the minimum recommended time).