The Sing If You Can presenter, played by comedian Leigh Francis, told Heat that the former X Factor duo are good singers.
Asked about the UK's chances, Lemon said: "I've not heard Blue's song ['I Can'], so I can't comment.
"But Jedward have got a good chance because I think they're on the right side of novelty. I don't mean that disrespectfully. I think they're fantastic vocalists. They can do cartwheels and sing.
"They did a cover of 'TiK ToK' on the show with Faye from Steps and they both front-flipped on. I went, 'This is f**king ace'."
Asked what advice he would give Jedward and Blue, he added: "Don't get drunk the night before. Or maybe do get drunk the night before. Sometimes I'm a bit more relaxed with a hangover. With Jedward, I'd say turn it up just an octave. Don't be so drab with your performance."
> Jedward: 'Our Eurovision entry is the best'
Watch the Jedward 'Lipstick' video below