The hosts were broadcasting the latest edition of the programme live from Westminster to report on Boris Johnson's future as the Prime Minister.
WATCH: GMB thrown into chaos as Susanna Reid interrupted by singing activist
Susanna was in the middle of updating viewers with the latest news about the cabinet resignations when she was interrupted by a speaker blasting Steve's rendition of the Bay City Rollers' 1975 song 'Bye Bye Baby'.
Instead of singing the original lyrics to the chorus, Steve could be heard belting out the words: "Bye Bye, Boris. Boris, goodbye."
The show later posted a clip of the hilarious moment to Twitter.
After hearing the first few moments of the song, a confused Susanna asked Ed: "Sorry, where's that come from? Are we about to do karaoke?"
"I think it must be a new Downing Street tactic," replied the former politician.
The hosts were interrupted by Steve Bray's singing
After hearing the chorus, Susanna realised that it was Steve carrying out his regular protest near parliament. She said: "It's the latest Steve Bray protest, isn't it?"
"Come on, Steve," added Ed.
"Well, I suppose if you're no longer allowed to shout, there are other ways of making your voice heard," said Susanna before handing over to fellow presenter Charlotte Hawkins in the studio.
Viewers were quick to react to the humorous moment, with one person tagging Steve on Twitter alongside the comment: "@snb19692 putting a smile on my face this morning on #GMB,' while another added: "Absolutely hilarious @GMB."
However, some viewers also took to Twitter for a different reason, divided over the show's special broadcast away from the ITV studio.
Steve Bray is known for his protests near parliament
One person questioned the show's decision to relocate for the day, writing: "Why do you have to be at the Houses of Parliament? It looks so much like a few people just standing around chatting. Get back in the studio," while another added: "Why on earth have #GMB got presenters outside Parliament on the lawn, adds nothing to the story at all."
However, others praised the new change, with one person writing: "Brilliant gmb team doing some great reporting this morning," while another applauded Ed's coverage: "Great to hear @edballs insight into the workings of parliament."
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