He’s quoted by The Sun newspaper’s Bizarre column as saying: “In truth it was a bit terrifying.
“I was also so excited about the idea of the shoot that I kind of forgot I was scared of heights until I got there and saw it. We were up there for just over an hour filming.
“I spent so much of it trying to stop my legs wobbling when I looked down that I felt like I had calves of steel when we finally got back to solid ground.”
Meanwhile, James previously revealed his childhood sweetheart Lucy Smith – who he has been with for 13 years now – was a driving force behind him pursuing his passion as a musician.
He recently said: “She’s the coolest person in the world. We were close friends before we were in a relationship.
“Back in the day, we would be sitting in on a Wednesday night watching TV, and she would say, ‘Hang on, if you want to be a big artist one day, surely you should be out in some pub or club playing some songs right now’.
“She instilled that in me, and I got out and did it. I wouldn’t be here without her.”
The 29-year-old singer has always been a “private person”, but he will open up about his relationship like never before on his upcoming – as yet untitled – third studio album.
He added: “I’m a really private person. My home life is a very intimate thing for me but I’m ready to talk about her for the first time.
“These next singles and album are a bit of a tribute to the 13-year journey my girlfriend and I have been on.”