The presenter, 61, took aim at the former boyband singer, 27, during an interview with him about taking part in Channel 4’s Celebrity Hunted.
McGuiness and his fellow Wanted star Siva Kaneswaran went on the run from professional hunters as part of the show and did quite well compared to the other celebrities on the show.
Co-host Ranvir Singh asked him how they managed to avoid detection: “What were your tricks?”
“We let go of any idea that we were going to look good and we were going to rough it – we got a tent,” McGuiness explained.
However, Madeley chipped in with an unexpected dig: “What? Like you have this morning?”
The pop star looked stunned by the comment but hit back: “Dude, don’t even get me started on your caramel highlights!”
His quip sent the presenters into stitches as Madeley stepped in to defend himself: “It’s a bit of sunshine. Everybody’s saying that – honestly, everyone thinks I’ve been the salon. I was just in France for a month.”
“God given, blessed,” joked McGuiness as Madeley said that comeback was “good”.
Talk turned to Strictly Come Dancing which McGuiness won in 2015 with professional Aliona Vilani.
Madeley made something of a blunder as he administered a backhanded compliment, telling him: “You’re not at all conceited at all.”
The musician didn’t look impressed and said: “Thanks.”
But the ITV star continued: “But at some point did you know that you would get to the final? Looking at the opposition, looking at your own performance and the votes you were getting, did you think ‘I might do this’.”
McGuiness explained: “That’s really hard because you live in a bubble where you’e reinforced by Wanted fans saying you’ve done amazing. But you don’t know how you come across.”
Good Morning Britain airs weekdays on ITV at 6am.