Piers Morgan called Health Secretary Matt Hancock a "shameless bullsh***er" in a furious Twitter swipe, after watching the MP's latest interview.
Mr Hancock, 41, appeared on BBC Breakfast this morning with Charlie Stayt, when the conversation turned to Brits quarantining after returning from abroad.
In a tense debate, the politician was forced to admit he didn't know how many travellers had been checked to see whether they had been obeying quarantine rules once they returned to the UK.
Though Mr Hancock originally claimed "we check it," BBC Breakfast's Charlie kept digging for answers, making it clear the MP didn't know the exact number of checks that had been carried out.
Apologising on-air, Mr Hancock said: "I'm terribly sorry I don't have the number of the precise people we have been in contact with and the size of that work. But I do know that the work is going on."
One viewer shared a clip of the moment on Twitter, writing: "Confusion on how many people are being checked to see if they are abiding by quarantine measures when coming back from Spain.
"Matt Hancock doesn't have an answer. #BBCBreakfast."
Good Morning Britain host Piers, who is currently holidaying in the south of France, watched the heated debate play out and decided to re-tweet the video.
In his caption, he took a swipe at Mr Hancock, saying: "Hancock is such a shameless bullsh***er.
"They have no idea how many are obeying the quarantine rules because I doubt they're even bothering to check."
This isn't the first time Piers has slammed Mr Hancock's leadership since the coronavirus pandemic began – he has a long history of berating the politician on-air.
Earlier this month, Piers accused the Health Secretary of "sneaking" back onto ITV after he left GMB for his annual leave, after months of an alleged government boycott of GMB.
After Mr Hancock appeared on Lorraine, Piers swiped: "Awww, look who sneaked back onto ITV the moment I left the country... it's our fearless Health Secretary Matt Hancock."
In another jibe, back in May, Piers tore into the politician after he accepted invitations to appear on This Morning and BBC Breakfast – but said no to GMB.
The outspoken GMB host snapped: "He's chosen an easy ride over tough questioning. Very unlike Mr Hancock who normally has the balls to defend his decisions. He's obviously now lost them."
Piers added: "Do you think it is right for the Health Secretary to boycott a major UK breakfast TV news show during the biggest health crisis for 100 years?
"Why are @GMB viewers not worthy of your time & vital information which might save their lives?"